Brush Keymap settings to override brush while holding a key.

Currently the keymap config allows brush strokes to be modified as they are performed, usually via inversion or overriding with Smooth brush.

However, I have found that some brushes for me are less ones you switch to for a period of time, and more so go back and forth from it to the main brush of a moment.

I would be a good quality of life feature to expand the Stroke Mode settings for keymap config to also include a custom brush in the library, such as Mask, filters, etc. It is certainly possible since it's exactly what Smooth does, just not hard locked to a specific brush. Granted, I don't have the knowledge to implement it myself...