A tool that adds extreme point under 45 degrees. default shortcut is cmd+shift+e. Constant angles across family help better interpolation. I recommend to use this tool in combination with 45 deg constrain. To activate it, tick the box in preferences/Glyph View saying use shift 45 deg constrain.
- Empty selection counts as the whole glyph was selected
- It rounds on-curve points that the extension added and ensures that its off-curve points are exactly 45 degrees when rounded to the grid.
- It only modifies selected segments, rest of the data stays untouched.
- It is prepared to support other angles in the future. Possibly also supporting step-checking of safe angles.