diff --git a/DEPRECATIONS.md b/DEPRECATIONS.md
index 5e917fa1..2ca30d7c 100644
--- a/DEPRECATIONS.md
+++ b/DEPRECATIONS.md
@@ -8,12 +8,6 @@ uv run python -m cellpy._deprecation
 
 | Name | Replacement | Introduced | Removal |
 | --- | --- | --- | --- |
-| `Batch.plot(backend="seaborn")` | `backend="matplotlib"` | 2.0 | 2.1 |
-| `cycle_info_plot(interactive=...)` | `backend="plotly"|"matplotlib"` | 2.0 | 2.1 |
-| `cycles_plot(interactive=...)` | `backend="plotly"|"matplotlib"` | 2.0 | 2.1 |
-| `cycles_plot(xlim=...)` | `cycles_plot(x_range=...)` | 2.0 | 2.1 |
-| `cycles_plot(ylim=...)` | `cycles_plot(y_range=...)` | 2.0 | 2.1 |
-| `dva_plot(interactive=...)` | `backend="plotly"|"matplotlib"` | 2.0 | 2.1 |
 | `ica.Converter` | `cellpy.ica.transform_half_cycle with IcaOptions` | 2.0 | 2.1 |
 | `ica.dqdv(cycle=...)` | `cellpy.ica.dqdv(cycles=...)` | 2.0 | 2.1 |
 | `ica.dqdv(label_direction=...)` | `the direction column, which the specced frame always carries` | 2.0 | 2.1 |
@@ -21,10 +15,6 @@ uv run python -m cellpy._deprecation
 | `ica.dqdv_cycle` | `cellpy.ica.dqdv (returns the specced long frame)` | 2.0 | 2.1 |
 | `ica.dqdv_cycles` | `cellpy.ica.dqdv (returns the specced long frame)` | 2.0 | 2.1 |
 | `ica.dqdv_np` | `cellpy.ica.transform_half_cycle with IcaOptions` | 2.0 | 2.1 |
-| `ica_plot(interactive=...)` | `backend="plotly"|"matplotlib"` | 2.0 | 2.1 |
 | `legacy header attribute access (headers_normal / _summary / _step_table)` | `c.schema.raw / c.schema.steps / c.schema.summary` | 2.0 | 2.1 |
 | `make_new_cell` | `CellpyCell.vacant` | 2.0 | 2.1 |
-| `plotutils.summary_plot_legacy` | `cellpy.utils.plotutils.summary_plot (same figures, same options)` | 2.0 | 2.1 |
-| `raw_plot(interactive=...)` | `backend="plotly"|"matplotlib"` | 2.0 | 2.1 |
-| `summary_plot(interactive=...)` | `backend="plotly"|"matplotlib"` | 2.0 | 2.1 |
 | `the 'dq' column of the ica output frame` | `the 'dqdv' column of the same frame` | 2.0 | 2.1 |
diff --git a/cellpy/_deprecation.py b/cellpy/_deprecation.py
index e4ae4101..edf85ffe 100644
--- a/cellpy/_deprecation.py
+++ b/cellpy/_deprecation.py
@@ -147,64 +147,8 @@ def _seed_known_deprecations() -> None:
         removal="2.1",
     )
 
-    # Plotting redesign (#567). The old implementation behind this name was
-    # unconditionally broken (its first statement unpacked a None); the name
-    # now delegates to summary_plot and goes away in 2.1.
-    _register(
-        "plotutils.summary_plot_legacy",
-        "cellpy.utils.plotutils.summary_plot (same figures, same options)",
-        removal="2.1",
-    )
-    # Stage 1 (#639): interactive= is a warn_once alias for backend=.
-    _register(
-        "summary_plot(interactive=...)",
-        'backend="plotly"|"matplotlib"',
-        removal="2.1",
-    )
-    # Stage 2 (#646): cycles_plot backend= + range spelling.
-    _register(
-        "cycles_plot(interactive=...)",
-        'backend="plotly"|"matplotlib"',
-        removal="2.1",
-    )
-    _register(
-        "cycles_plot(xlim=...)",
-        "cycles_plot(x_range=...)",
-        removal="2.1",
-    )
-    _register(
-        "cycles_plot(ylim=...)",
-        "cycles_plot(y_range=...)",
-        removal="2.1",
-    )
-    # Stage 2 (#647): raw_plot / cycle_info_plot backend=.
-    _register(
-        "raw_plot(interactive=...)",
-        'backend="plotly"|"matplotlib"',
-        removal="2.1",
-    )
-    _register(
-        "cycle_info_plot(interactive=...)",
-        'backend="plotly"|"matplotlib"',
-        removal="2.1",
-    )
-    # Stage 2 (#648): ica_plot / dva_plot backend=.
-    _register(
-        "ica_plot(interactive=...)",
-        'backend="plotly"|"matplotlib"',
-        removal="2.1",
-    )
-    _register(
-        "dva_plot(interactive=...)",
-        'backend="plotly"|"matplotlib"',
-        removal="2.1",
-    )
-    # Stage 3 (#658): Batch.plot backend triage — seaborn alias, bokeh removed.
-    _register(
-        'Batch.plot(backend="seaborn")',
-        'backend="matplotlib"',
-        removal="2.1",
-    )
+    # Plotting shims (interactive=, xlim/ylim, backend="seaborn", summary_plot_legacy)
+    # were removed in 2.1 (E1, #713) -- no longer registered here.
 
 
 if __name__ == "__main__":
diff --git a/cellpy/plotting/batch_summary.py b/cellpy/plotting/batch_summary.py
index ed761279..2ef97e1a 100644
--- a/cellpy/plotting/batch_summary.py
+++ b/cellpy/plotting/batch_summary.py
@@ -2,8 +2,7 @@
 
 Relocated from ``cellpy.utils.batch_tools.batch_plotters`` so ``Batch.plot``
 delegates into ``cellpy.plotting``. Public backends: ``plotly`` (primary) and
-``matplotlib``. ``seaborn`` is a deprecated alias for ``matplotlib``; ``bokeh``
-raises.
+``matplotlib``. ``seaborn`` and ``bokeh`` were removed in 2.1 and now raise.
 """
 
 from __future__ import annotations
@@ -34,22 +33,13 @@
 
 
 def resolve_batch_plot_backend(backend: Optional[str]) -> str:
-    """Normalize Batch.plot backend names (triage for #658)."""
-    from cellpy._deprecation import warn_once
-
+    """Normalize Batch.plot backend names."""
     if backend is None:
         backend = getattr(config.batch, "backend", None) or "plotly"
     key = str(backend).strip().lower()
-    if key == "seaborn":
-        warn_once(
-            'Batch.plot(backend="seaborn")',
-            'backend="matplotlib"',
-            stacklevel=3,
-        )
-        key = "matplotlib"
-    if key == "bokeh":
+    if key in ("seaborn", "bokeh"):
         raise ValueError(
-            'Batch.plot backend "bokeh" was removed; use backend="plotly" '
+            f'Batch.plot backend "{key}" was removed; use backend="plotly" '
             'or backend="matplotlib".'
         )
     if key not in SUPPORTED_BATCH_PLOT_BACKENDS:
diff --git a/cellpy/utils/plotutils.py b/cellpy/utils/plotutils.py
index 778ee215..ba2f2e16 100644
--- a/cellpy/utils/plotutils.py
+++ b/cellpy/utils/plotutils.py
@@ -607,7 +607,6 @@ class SummaryPlotConfig:
     hover_columns: Optional[list] = None
     auto_convert_legend_labels: bool = True
     backend: Optional[str] = None
-    interactive: Optional[bool] = None
     share_y: bool = False
     rangeslider: bool = False
 
@@ -920,97 +919,6 @@ def _create_col_info(self, c: Any) -> tuple[tuple, dict, dict, dict]:
 
 
 
-def summary_plot_legacy(
-    c,
-    x: Optional[str] = None,
-    y: str = "capacities_gravimetric_coulombic_efficiency",
-    height: Optional[int] = None,
-    width: int = 900,
-    markers: bool = True,
-    title: Optional[str] = None,
-    x_range: Optional[list] = None,
-    y_range: Optional[list] = None,
-    ce_range: Optional[list] = None,
-    norm_range: Optional[list] = None,
-    cv_share_range: Optional[list] = None,
-    split: bool = True,
-    auto_convert_legend_labels: bool = True,
-    interactive: bool = True,
-    share_y: bool = False,
-    rangeslider: bool = False,
-    return_data: bool = False,
-    verbose: bool = False,
-    plotly_template: Optional[str] = None,
-    seaborn_palette: str = "deep",
-    seaborn_style: str = "dark",
-    formation_cycles: int = 3,
-    show_formation: bool = True,
-    show_legend: bool = True,
-    x_axis_domain_formation_fraction: float = 0.2,
-    column_separator: float = 0.01,
-    reset_losses: bool = True,
-    link_capacity_scales: bool = False,
-    fullcell_standard_normalization_type: str = "on-max",
-    fullcell_standard_normalization_factor: Optional[float] = None,
-    fullcell_standard_normalization_scaler: float = 1.0,
-    seaborn_line_hooks: Optional[list[tuple[str, list, dict]]] = None,
-    **kwargs,
-) -> Any:
-    """Deprecated. Use [`summary_plot`][cellpy.utils.plotutils.summary_plot].
-
-    The 1 400-line implementation that used to live here was **broken, not
-    merely redundant**: its first statement unpacked the return value of
-    ``SummaryPlotInfo._create_col_info``, which stores its results as
-    attributes and returns ``None`` — so every call raised ``TypeError``
-    regardless of the cell or the runtime (#567). Nothing in the repo called
-    it, and nothing outside it could have called it successfully either.
-
-    Delegates to ``summary_plot``, which draws the same figures through the
-    builder pipeline. Removal in 2.1.
-    """
-    warn_once(
-        "plotutils.summary_plot_legacy",
-        "cellpy.utils.plotutils.summary_plot (same figures, same options)",
-        removal="2.1",
-    )
-    return summary_plot(
-        c,
-        x=x,
-        y=y,
-        height=height,
-        width=width,
-        markers=markers,
-        title=title,
-        x_range=x_range,
-        y_range=y_range,
-        ce_range=ce_range,
-        norm_range=norm_range,
-        cv_share_range=cv_share_range,
-        split=split,
-        auto_convert_legend_labels=auto_convert_legend_labels,
-        interactive=interactive,
-        share_y=share_y,
-        rangeslider=rangeslider,
-        return_data=return_data,
-        verbose=verbose,
-        plotly_template=plotly_template,
-        seaborn_palette=seaborn_palette,
-        seaborn_style=seaborn_style,
-        formation_cycles=formation_cycles,
-        show_formation=show_formation,
-        show_legend=show_legend,
-        x_axis_domain_formation_fraction=x_axis_domain_formation_fraction,
-        column_separator=column_separator,
-        reset_losses=reset_losses,
-        link_capacity_scales=link_capacity_scales,
-        fullcell_standard_normalization_type=fullcell_standard_normalization_type,
-        fullcell_standard_normalization_factor=fullcell_standard_normalization_factor,
-        fullcell_standard_normalization_scaler=fullcell_standard_normalization_scaler,
-        seaborn_line_hooks=seaborn_line_hooks,
-        **kwargs,
-    )
-
-
 @notebook_docstring_printer
 def summary_plot(
     c,
@@ -1029,7 +937,6 @@ def summary_plot(
     hover_columns: Optional[list] = None,
     auto_convert_legend_labels: bool = True,
     backend: Optional[str] = None,
-    interactive: Optional[bool] = None,
     share_y: bool = False,
     rangeslider: bool = False,
     return_data: bool = False,
@@ -1081,8 +988,6 @@ def summary_plot(
         auto_convert_legend_labels: convert the legend labels to a nicer format.
         backend: plotting backend (``"plotly"`` or ``"matplotlib"``; default
             ``"plotly"``)
-        interactive: deprecated alias for backend selection
-            (``True`` → ``"plotly"``, ``False`` → ``"matplotlib"``); removal 2.1
         rangeslider: add a range slider to the x-axis (only for plotly)
         share_y: share y-axis (only for plotly)
         return_data: return the data used for plotting
@@ -1219,7 +1124,6 @@ def summary_plot(
         hover_columns=hover_columns,
         auto_convert_legend_labels=auto_convert_legend_labels,
         backend=backend,
-        interactive=interactive,
         share_y=share_y,
         rangeslider=rangeslider,
         return_data=return_data,
@@ -1250,18 +1154,7 @@ def summary_plot(
     config.x = _resolve_summary_column(c, config.x)
     config.hover_columns = _resolve_summary_columns(c, config.hover_columns)
 
-    # Resolve backend= vs deprecated interactive= (#639).
-    resolved_backend = config.backend
-    if config.interactive is not None:
-        warn_once(
-            "summary_plot(interactive=...)",
-            'backend="plotly"|"matplotlib"',
-            removal="2.1",
-        )
-        if resolved_backend is None:
-            resolved_backend = "plotly" if config.interactive else "matplotlib"
-    if resolved_backend is None:
-        resolved_backend = "plotly"
+    resolved_backend = config.backend or "plotly"
     config.backend = resolved_backend
 
     if resolved_backend == "plotly" and not plotly_available:
@@ -1367,7 +1260,6 @@ def raw_plot(
     x_label=None,
     title=None,
     backend: Optional[str] = None,
-    interactive: Optional[bool] = None,
     plot_type="voltage-current",
     double_y=True,
     **kwargs,
@@ -1384,8 +1276,6 @@ def raw_plot(
         x_label (str): label for x-axis
         title (str): title of the plot
         backend (str, optional): ``"plotly"`` (default) or ``"matplotlib"``.
-        interactive (bool, optional): Deprecated alias for backend selection
-            (``True``→plotly, ``False``→matplotlib; removal 2.1).
         plot_type (str): type of plot (defaults to "voltage-current") (overrides given y if y is not None),
           currently only "voltage-current", "raw", "capacity", "capacity-current", and "full" is supported.
         double_y (bool): use double y-axis (only for matplotlib and when plot_type with 2 rows is used)
@@ -1395,17 +1285,7 @@ def raw_plot(
         ``matplotlib`` figure or ``plotly`` figure
 
     """
-    resolved_backend = backend
-    if interactive is not None:
-        warn_once(
-            "raw_plot(interactive=...)",
-            'backend="plotly"|"matplotlib"',
-            removal="2.1",
-        )
-        if resolved_backend is None:
-            resolved_backend = "plotly" if interactive else "matplotlib"
-    if resolved_backend is None:
-        resolved_backend = "plotly"
+    resolved_backend = backend or "plotly"
 
     if resolved_backend == "plotly" and not plotly_available:
         warnings.warn("Can not perform interactive plotting. Plotly is not available.")
@@ -1442,7 +1322,6 @@ def cycle_info_plot(
     cycle=None,
     get_axes=False,
     backend: Optional[str] = None,
-    interactive: Optional[bool] = None,
     t_unit="hours",
     v_unit="V",
     i_unit="mA",
@@ -1457,8 +1336,6 @@ def cycle_info_plot(
         cycle (int or list or tuple): cycle(s) to select (must be int for matplotlib)
         get_axes (bool): return axes (for matplotlib) or figure (for plotly)
         backend (str, optional): ``"plotly"`` (default) or ``"matplotlib"``.
-        interactive (bool, optional): Deprecated alias for backend selection
-            (``True``→plotly, ``False``→matplotlib; removal 2.1).
         t_unit (str): unit for x-axis (default: "hours")
         v_unit (str): unit for y-axis (default: "V")
         i_unit (str): unit for current (default: "mA")
@@ -1467,17 +1344,7 @@ def cycle_info_plot(
     Returns:
         ``matplotlib.axes`` or None (or a figure when ``get_axes`` / backend semantics require it)
     """
-    resolved_backend = backend
-    if interactive is not None:
-        warn_once(
-            "cycle_info_plot(interactive=...)",
-            'backend="plotly"|"matplotlib"',
-            removal="2.1",
-        )
-        if resolved_backend is None:
-            resolved_backend = "plotly" if interactive else "matplotlib"
-    if resolved_backend is None:
-        resolved_backend = "plotly"
+    resolved_backend = backend or "plotly"
 
     if resolved_backend == "plotly" and not plotly_available:
         warnings.warn("Can not perform interactive plotting. Plotly is not available.")
@@ -1536,10 +1403,7 @@ def cycles_plot(
     figsize=(6, 4),
     x_range=None,
     y_range=None,
-    xlim=None,
-    ylim=None,
     backend: Optional[str] = None,
-    interactive: Optional[bool] = None,
     return_figure=None,
     width=800,
     height=600,
@@ -1580,11 +1444,7 @@ def cycles_plot(
         figsize (tuple, optional): Size of the figure for matplotlib. Default is (6, 4).
         x_range (list, optional): Limits for the x-axis.
         y_range (list, optional): Limits for the y-axis.
-        xlim (list, optional): Deprecated alias for ``x_range`` (removal 2.1).
-        ylim (list, optional): Deprecated alias for ``y_range`` (removal 2.1).
         backend (str, optional): ``"plotly"`` (default) or ``"matplotlib"``.
-        interactive (bool, optional): Deprecated alias for backend selection
-            (``True``→plotly, ``False``→matplotlib; removal 2.1).
         return_figure (bool, optional): Whether to return the figure object.
             Default is ``True`` for matplotlib and ``False`` for plotly (``fig.show()``).
         width (int, optional): Width of the figure for Plotly. Default is 800.
@@ -1614,18 +1474,7 @@ def cycles_plot(
         Else:
             None: The plot is shown in the default browser.
     """
-    # Resolve backend= vs deprecated interactive= (#646 / same as #639).
-    resolved_backend = backend
-    if interactive is not None:
-        warn_once(
-            "cycles_plot(interactive=...)",
-            'backend="plotly"|"matplotlib"',
-            removal="2.1",
-        )
-        if resolved_backend is None:
-            resolved_backend = "plotly" if interactive else "matplotlib"
-    if resolved_backend is None:
-        resolved_backend = "plotly"
+    resolved_backend = backend or "plotly"
 
     if resolved_backend == "plotly" and not plotly_available:
         warnings.warn("Can not perform interactive plotting. Plotly is not available.")
@@ -1634,24 +1483,6 @@ def cycles_plot(
     if return_figure is None:
         return_figure = resolved_backend != "plotly"
 
-    # Canonical range spelling: x_range/y_range; xlim/ylim are warn_once aliases.
-    if xlim is not None:
-        warn_once(
-            "cycles_plot(xlim=...)",
-            "cycles_plot(x_range=...)",
-            removal="2.1",
-        )
-        if x_range is None:
-            x_range = xlim
-    if ylim is not None:
-        warn_once(
-            "cycles_plot(ylim=...)",
-            "cycles_plot(y_range=...)",
-            removal="2.1",
-        )
-        if y_range is None:
-            y_range = ylim
-
     seaborn_context = kwargs.pop("seaborn_context", "notebook")
     seaborn_facecolor = kwargs.pop("seaborn_facecolor", "#EAEAF2")
     seaborn_edgecolor = kwargs.pop("seaborn_edgecolor", "black")
@@ -1712,24 +1543,9 @@ def cycles_plot(
     return None
 
 
-def _resolve_plot_backend(
-    *,
-    backend: Optional[str],
-    interactive: Optional[bool],
-    deprecation_site: str,
-) -> str:
-    """Resolve ``backend=`` vs deprecated ``interactive=`` for plot entry points."""
-    resolved = backend
-    if interactive is not None:
-        warn_once(
-            deprecation_site,
-            'backend="plotly"|"matplotlib"',
-            removal="2.1",
-        )
-        if resolved is None:
-            resolved = "plotly" if interactive else "matplotlib"
-    if resolved is None:
-        resolved = "plotly"
+def _resolve_plot_backend(backend: Optional[str]) -> str:
+    """Resolve the plotting backend for plot entry points (default ``plotly``)."""
+    resolved = backend or "plotly"
     if resolved == "plotly" and not plotly_available:
         warnings.warn("Can not perform interactive plotting. Plotly is not available.")
         resolved = "matplotlib"
@@ -1743,7 +1559,6 @@ def ica_plot(
     options=None,
     *,
     backend: Optional[str] = None,
-    interactive: Optional[bool] = None,
     title=None,
     colormap="viridis",
     width=800,
@@ -1767,7 +1582,6 @@ def ica_plot(
         direction: ``"charge"``, ``"discharge"``, or ``"both"``.
         options: Optional [`IcaOptions`][cellpy.ica.IcaOptions].
         backend: ``"plotly"`` (default) or ``"matplotlib"``.
-        interactive: Deprecated alias for backend selection (removal 2.1).
         title: Figure title.
         colormap: Cycle colour map.
         width, height: Plotly figure size.
@@ -1785,11 +1599,7 @@ def ica_plot(
     from cellpy.plotting.context import from_source
     from cellpy.plotting.prepare.ica import IcaPrepareConfig, prepare as prepare_ica
 
-    resolved_backend = _resolve_plot_backend(
-        backend=backend,
-        interactive=interactive,
-        deprecation_site="ica_plot(interactive=...)",
-    )
+    resolved_backend = _resolve_plot_backend(backend)
 
     option_keys = {
         "voltage_resolution",
@@ -1850,7 +1660,6 @@ def dva_plot(
     options=None,
     *,
     backend: Optional[str] = None,
-    interactive: Optional[bool] = None,
     title=None,
     colormap="viridis",
     width=800,
@@ -1875,7 +1684,6 @@ def dva_plot(
         options: Optional [`IcaOptions`][cellpy.ica.IcaOptions] (defaults to
             DVA-oriented options inside ``dvdq``).
         backend: ``"plotly"`` (default) or ``"matplotlib"``.
-        interactive: Deprecated alias for backend selection (removal 2.1).
         title: Figure title.
         colormap: Cycle colour map.
         width, height: Plotly figure size.
@@ -1893,11 +1701,7 @@ def dva_plot(
     from cellpy.plotting.context import from_source
     from cellpy.plotting.prepare.ica import IcaPrepareConfig, prepare as prepare_ica
 
-    resolved_backend = _resolve_plot_backend(
-        backend=backend,
-        interactive=interactive,
-        deprecation_site="dva_plot(interactive=...)",
-    )
+    resolved_backend = _resolve_plot_backend(backend)
 
     option_keys = {
         "voltage_resolution",
@@ -1984,11 +1788,11 @@ def _check_plotter_plotly():
     c = cellpy.get(p)
     fig = cycles_plot(
         c,
-        ylim=[0.0, 1.0],
+        y_range=[0.0, 1.0],
         show_formation=False,
         cut_colorbar=False,
         title="My nice plot",
-        interactive=True,
+        backend="plotly",
         return_figure=True,
     )
     print("saving figure")
@@ -2011,11 +1815,11 @@ def _check_plotter_matplotlib():
     c = cellpy.get(p)
     fig = cycles_plot(
         c,
-        ylim=[0.0, 1.0],
+        y_range=[0.0, 1.0],
         show_formation=False,
         cut_colorbar=False,
         title="My nice plot",
-        interactive=False,
+        backend="matplotlib",
         return_figure=True,
     )
     print("saving figure")
@@ -2044,7 +1848,7 @@ def _check_summary_plotter_plotly():
         # cut_colorbar=False,
         # split=True,
         title="My nice plot",
-        interactive=True,  # rangeslider=True,
+        backend="plotly",  # rangeslider=True,
         show_formation=True,
         # return_data=False,
     )
@@ -2078,7 +1882,7 @@ def _check_summary_plotter_seaborn():
         # cut_colorbar=False,
         # split=True,
         title="My nice plot",
-        interactive=False,  # rangeslider=True,
+        backend="matplotlib",  # rangeslider=True,
         show_formation=True,  # return_figure=True,
     )
     # print("saving figure")
@@ -2098,7 +1902,7 @@ def _check_cycles_plotter_plotly():
         c,
         y="capacities_gravimetric",
         cycles=[1, 2, 3, 4, 5, 20, 40, 60],
-        interactive=True,
+        backend="plotly",
         return_figure=True,
     )
     save_image_files(fig, out / "test_plot_cycles_plotly", backend="plotly")
@@ -2114,7 +1918,7 @@ def _check_cycles_plotter_matplotlib():
     fig = cycles_plot(
         c,
         y="capacities_gravimetric",
-        interactive=False,
+        backend="matplotlib",
         return_figure=True,
     )
     save_image_files(fig, out / "test_plot_cycles_matplotlib", backend="matplotlib")
diff --git a/tests/test_batch.py b/tests/test_batch.py
index b7ea4924..9c6f95bb 100644
--- a/tests/test_batch.py
+++ b/tests/test_batch.py
@@ -799,13 +799,13 @@ def test_batch_update(parameters, batch_instance):
 
 @pytest.mark.essential
 def test_batch_plot_backend_triage():
-    """seaborn → matplotlib (warn); bokeh → ValueError (#658)."""
+    """plotly/matplotlib supported; seaborn + bokeh removed in 2.1 (E1, #713)."""
     from cellpy.plotting.batch_summary import resolve_batch_plot_backend
 
     assert resolve_batch_plot_backend("plotly") == "plotly"
     assert resolve_batch_plot_backend("matplotlib") == "matplotlib"
-    with pytest.warns(DeprecationWarning, match="seaborn"):
-        assert resolve_batch_plot_backend("seaborn") == "matplotlib"
+    with pytest.raises(ValueError, match="seaborn"):
+        resolve_batch_plot_backend("seaborn")
     with pytest.raises(ValueError, match="bokeh"):
         resolve_batch_plot_backend("bokeh")
     with pytest.raises(ValueError, match="not supported"):
diff --git a/tests/test_cycles_prepare.py b/tests/test_cycles_prepare.py
index cef8f29d..b79aefd5 100644
--- a/tests/test_cycles_prepare.py
+++ b/tests/test_cycles_prepare.py
@@ -41,42 +41,17 @@ def test_cycles_plot_backend_matplotlib(cell):
 
 
 @pytest.mark.essential
-def test_cycles_plot_interactive_alias_warns(cell):
-    from cellpy import _deprecation
-
-    _deprecation._WARNED_SITES.clear()
-    with warnings.catch_warnings(record=True) as caught:
-        warnings.simplefilter("always", DeprecationWarning)
-        fig = cycles_plot(cell, interactive=False, return_figure=True)
-    assert fig is not None
-    messages = [
-        str(w.message)
-        for w in caught
-        if issubclass(w.category, DeprecationWarning)
-        and "interactive" in str(w.message)
-    ]
-    assert messages
-    assert "backend=" in messages[0] or "matplotlib" in messages[0]
-
-
-@pytest.mark.essential
-def test_cycles_plot_xlim_ylim_alias_warns(cell):
-    from cellpy import _deprecation
-
-    _deprecation._WARNED_SITES.clear()
-    with warnings.catch_warnings(record=True) as caught:
-        warnings.simplefilter("always", DeprecationWarning)
-        fig = cycles_plot(
-            cell,
-            backend="matplotlib",
-            xlim=[0, 1],
-            ylim=[0, 2],
-            return_figure=True,
-        )
+def test_cycles_plot_interactive_and_range_shims_removed(cell):
+    # interactive=/xlim/ylim were removed in 2.1 (E1, #713); canonical spellings only.
+    import inspect
+
+    params = inspect.signature(cycles_plot).parameters
+    assert "interactive" not in params
+    assert "xlim" not in params and "ylim" not in params
+    fig = cycles_plot(
+        cell, backend="matplotlib", x_range=[0, 1], y_range=[0, 2], return_figure=True
+    )
     assert fig is not None
-    texts = [str(w.message) for w in caught if issubclass(w.category, DeprecationWarning)]
-    assert any("xlim" in t for t in texts)
-    assert any("ylim" in t for t in texts)
 
 
 @pytest.mark.essential
diff --git a/tests/test_figure_specs.py b/tests/test_figure_specs.py
index d94f58ff..ad2d1071 100644
--- a/tests/test_figure_specs.py
+++ b/tests/test_figure_specs.py
@@ -178,7 +178,7 @@ def test_plotting_does_not_mutate_the_cell(cell):
     from cellpy.utils.plotutils import summary_plot
 
     summary_plot(
-        cell, y="capacities_gravimetric_split_constant_voltage", interactive=False
+        cell, y="capacities_gravimetric_split_constant_voltage", backend="matplotlib"
     )
 
     assert list(cell.data.summary.columns) == summary_before
diff --git a/tests/test_ica_plot_prepare.py b/tests/test_ica_plot_prepare.py
index 988fba86..5bb1c491 100644
--- a/tests/test_ica_plot_prepare.py
+++ b/tests/test_ica_plot_prepare.py
@@ -71,37 +71,10 @@ def test_dva_plot_backend_matplotlib(cell):
 
 
 @pytest.mark.essential
-def test_ica_plot_interactive_alias_warns(cell):
-    from cellpy import _deprecation
+def test_ica_dva_interactive_removed(cell):
+    import inspect
 
-    _deprecation._WARNED_SITES.clear()
-    with warnings.catch_warnings(record=True) as caught:
-        warnings.simplefilter("always", DeprecationWarning)
-        fig = ica_plot(cell, cycles=1, interactive=False)
-    assert fig is not None
-    messages = [
-        str(w.message)
-        for w in caught
-        if issubclass(w.category, DeprecationWarning)
-        and "interactive" in str(w.message)
-    ]
-    assert messages
-    assert "backend=" in messages[0] or "matplotlib" in messages[0]
-
-
-@pytest.mark.essential
-def test_dva_plot_interactive_alias_warns(cell):
-    from cellpy import _deprecation
-
-    _deprecation._WARNED_SITES.clear()
-    with warnings.catch_warnings(record=True) as caught:
-        warnings.simplefilter("always", DeprecationWarning)
-        fig = dva_plot(cell, cycles=1, interactive=False)
-    assert fig is not None
-    messages = [
-        str(w.message)
-        for w in caught
-        if issubclass(w.category, DeprecationWarning)
-        and "interactive" in str(w.message)
-    ]
-    assert messages
+    assert "interactive" not in inspect.signature(ica_plot).parameters
+    assert "interactive" not in inspect.signature(dva_plot).parameters
+    assert ica_plot(cell, cycles=1, backend="matplotlib") is not None
+    assert dva_plot(cell, cycles=1, backend="matplotlib") is not None
diff --git a/tests/test_mpl_backend.py b/tests/test_mpl_backend.py
index a38c3b73..31c0f25f 100644
--- a/tests/test_mpl_backend.py
+++ b/tests/test_mpl_backend.py
@@ -34,29 +34,18 @@ def test_seaborn_plot_builder_is_gone():
 
 
 @pytest.mark.essential
-def test_interactive_alias_warns_and_maps(cell):
-    from cellpy import _deprecation
+def test_interactive_kwarg_removed(cell):
+    # interactive= was removed in 2.1 (E1, #713); backend= is canonical.
+    import inspect
 
-    # warn_once is once-per-call-site across the whole process; reset so this
-    # test is order-independent in the essential suite.
-    _deprecation._WARNED_SITES.clear()
-    with warnings.catch_warnings(record=True) as caught:
-        warnings.simplefilter("always", DeprecationWarning)
-        fig = summary_plot(
-            cell,
-            y="capacities_gravimetric",
-            interactive=False,
-            show_formation=False,
-        )
+    assert "interactive" not in inspect.signature(summary_plot).parameters
+    fig = summary_plot(
+        cell,
+        y="capacities_gravimetric",
+        backend="matplotlib",
+        show_formation=False,
+    )
     assert fig is not None
-    messages = [
-        str(w.message)
-        for w in caught
-        if issubclass(w.category, DeprecationWarning)
-        and "interactive" in str(w.message)
-    ]
-    assert messages, "expected DeprecationWarning for interactive="
-    assert "backend=" in messages[0] or "matplotlib" in messages[0]
 
 
 @pytest.mark.essential
diff --git a/tests/test_plotutils_headers.py b/tests/test_plotutils_headers.py
index c82a1618..df206c09 100644
--- a/tests/test_plotutils_headers.py
+++ b/tests/test_plotutils_headers.py
@@ -102,12 +102,12 @@ def test_normalized_cycle_index_is_dialect_invariant():
 
 
 @pytest.mark.essential
-@pytest.mark.parametrize("interactive", [False, True])
-def test_raw_plot_runs_on_a_native_cell(cell, interactive):
+@pytest.mark.parametrize("backend", ["matplotlib", "plotly"])
+def test_raw_plot_runs_on_a_native_cell(cell, backend):
     """`raw_plot` raised KeyError: 'voltage' on every cellpy 2 cell."""
-    if interactive and not plotly_available:
+    if backend == "plotly" and not plotly_available:
         pytest.skip("plotly not installed")
-    figure = plotutils.raw_plot(cell, interactive=interactive)
+    figure = plotutils.raw_plot(cell, backend=backend)
     assert figure is not None
 
 
@@ -115,17 +115,17 @@ def test_raw_plot_runs_on_a_native_cell(cell, interactive):
 @pytest.mark.parametrize("plot_type", ["voltage-current", "capacity", "raw"])
 def test_raw_plot_predefined_types_run(cell, plot_type):
     """Each plot_type reaches a different set of raw columns."""
-    figure = plotutils.raw_plot(cell, interactive=False, plot_type=plot_type)
+    figure = plotutils.raw_plot(cell, backend="matplotlib", plot_type=plot_type)
     assert figure is not None
 
 
 @pytest.mark.essential
-@pytest.mark.parametrize("interactive", [False, True])
-def test_cycle_info_plot_runs_on_a_native_cell(cell, interactive):
+@pytest.mark.parametrize("backend", ["matplotlib", "plotly"])
+def test_cycle_info_plot_runs_on_a_native_cell(cell, backend):
     """`cycle_info_plot` raised on both the raw and the step frame."""
-    if interactive and not plotly_available:
+    if backend == "plotly" and not plotly_available:
         pytest.skip("plotly not installed")
-    plotutils.cycle_info_plot(cell, cycle=3, interactive=interactive)
+    plotutils.cycle_info_plot(cell, cycle=3, backend=backend)
 
 
 # --- user-supplied column names ----------------------------------------------
@@ -136,7 +136,7 @@ def test_cycle_info_plot_runs_on_a_native_cell(cell, interactive):
 def test_summary_plot_accepts_the_legacy_x_spelling(cell):
     """`x="cycle_index"` is what this module's own docstring tells you to pass."""
     figure = plotutils.summary_plot(
-        cell, y="capacities_gravimetric", x="cycle_index", interactive=False
+        cell, y="capacities_gravimetric", x="cycle_index", backend="matplotlib"
     )
     assert figure is not None
 
@@ -145,7 +145,7 @@ def test_summary_plot_accepts_the_legacy_x_spelling(cell):
 @pytest.mark.skipif(not seaborn_available, reason="seaborn not installed")
 def test_summary_plot_accepts_the_native_x_spelling(cell):
     figure = plotutils.summary_plot(
-        cell, y="capacities_gravimetric", x="cycle_num", interactive=False
+        cell, y="capacities_gravimetric", x="cycle_num", backend="matplotlib"
     )
     assert figure is not None
 
@@ -175,50 +175,18 @@ def test_cv_split_plot_leaves_the_summary_frame_alone(cell):
     """
     before = list(cell.data.summary.columns)
     plotutils.summary_plot(
-        cell, y="capacities_gravimetric_split_constant_voltage", interactive=False
+        cell, y="capacities_gravimetric_split_constant_voltage", backend="matplotlib"
     )
     assert list(cell.data.summary.columns) == before
     assert cell.data.summary.index.name != "cycle_num"
 
 
-# --- summary_plot_legacy is a delegate now ------------------------------------
+# --- summary_plot_legacy was removed in 2.1 (E1, #713) ------------------------
 
 
 @pytest.mark.essential
-@pytest.mark.skipif(not seaborn_available, reason="seaborn not installed")
-def test_summary_plot_legacy_delegates_and_warns(cell):
-    """The old implementation could not draw anything at all.
-
-    Its first statement unpacked the return value of
-    `SummaryPlotInfo._create_col_info`, which stores its results as attributes
-    and returns None — so every call raised TypeError, on any cell, since the
-    refactor that introduced the class (#567). The name now delegates to
-    summary_plot, which is strictly better than the TypeError callers got.
-    """
-    import warnings as _warnings
-
-    from tests.figure_spec_support import describe_figure
-
-    with _warnings.catch_warnings(record=True) as caught:
-        _warnings.simplefilter("always")
-        via_legacy = plotutils.summary_plot_legacy(
-            cell, y="capacities_gravimetric", interactive=False
-        )
-    assert any(
-        issubclass(w.category, DeprecationWarning)
-        and "summary_plot_legacy" in str(w.message)
-        for w in caught
-    )
-
-    direct = plotutils.summary_plot(
-        cell, y="capacities_gravimetric", interactive=False
-    )
-    assert describe_figure(via_legacy) == describe_figure(direct)
-
-    import matplotlib.pyplot as plt
-
-    plt.close(via_legacy)
-    plt.close(direct)
+def test_summary_plot_legacy_removed():
+    assert not hasattr(plotutils, "summary_plot_legacy")
 
 
 @pytest.mark.essential
diff --git a/tests/test_raw_cycle_info_prepare.py b/tests/test_raw_cycle_info_prepare.py
index c17783e8..02a9f66e 100644
--- a/tests/test_raw_cycle_info_prepare.py
+++ b/tests/test_raw_cycle_info_prepare.py
@@ -64,36 +64,10 @@ def test_cycle_info_plot_backend_matplotlib(cell):
 
 
 @pytest.mark.essential
-def test_raw_plot_interactive_alias_warns(cell):
-    from cellpy import _deprecation
+def test_raw_and_cycle_info_interactive_removed(cell):
+    import inspect
 
-    _deprecation._WARNED_SITES.clear()
-    with warnings.catch_warnings(record=True) as caught:
-        warnings.simplefilter("always", DeprecationWarning)
-        fig = raw_plot(cell, interactive=False)
-    assert fig is not None
-    messages = [
-        str(w.message)
-        for w in caught
-        if issubclass(w.category, DeprecationWarning)
-        and "interactive" in str(w.message)
-    ]
-    assert messages
-    assert "backend=" in messages[0] or "matplotlib" in messages[0]
-
-
-@pytest.mark.essential
-def test_cycle_info_plot_interactive_alias_warns(cell):
-    from cellpy import _deprecation
-
-    _deprecation._WARNED_SITES.clear()
-    with warnings.catch_warnings(record=True) as caught:
-        warnings.simplefilter("always", DeprecationWarning)
-        cycle_info_plot(cell, cycle=3, interactive=False)
-    messages = [
-        str(w.message)
-        for w in caught
-        if issubclass(w.category, DeprecationWarning)
-        and "interactive" in str(w.message)
-    ]
-    assert messages
+    assert "interactive" not in inspect.signature(raw_plot).parameters
+    assert "interactive" not in inspect.signature(cycle_info_plot).parameters
+    assert raw_plot(cell, backend="matplotlib") is not None
+    cycle_info_plot(cell, cycle=3, backend="matplotlib")