1: The option for users to set up a painting in a more print friendly colour space like CMYK. I think this is something a lot of print focused users would appreciate.

2: Panels (particularly the Tool Presets panel!); could they show things alphanumerically?
It would make finding things a lot easier when you have a lot of groups to wade through. At present there seems no obvious logical structure as to how things are being ordered.
Also perhaps a Search filed at the top of a panel could be useful. Start typing and AR will take you to the Group or brush you are looking for within that panel. Useful if you know what the brush is you are looking for but can’t remember which group you put it.

3: Could Canvas Zoom be focused on tool/cursor position?