The Line Lists Plugin <mosviz-line-lists> contains a redshift slider as well as the ability to view and set the redshift and/or radial velocity.
Additionally, the Line Analysis Plugin <line-analysis> includes the capability to compute and assign the redshift based on the measured centroid of a line.
In the notebook, the value of the Redshift column can be changed for all rows or a single row using :py~jdaviz.configs.mosviz.helper.Mosviz.update_column.
The 1D and 2D spectrum objects can be retrieved (with redshift optionally applied) using :py~jdaviz.configs.mosviz.helper.Mosviz.get_spectrum_1d and :py~jdaviz.configs.mosviz.helper.Mosviz.get_spectrum_2d, respectively.
See the notebooks/MosvizNIRISSExample.ipynb notebook in the repository to see examples of manipulating MOS Table data, including the redshift.