The new ability to make a custom toolbar is great, but it's limited to existing tools only. It'd be great to be able to add items from the menus that are sometimes buried several clicks in - such as Select Same Appearance, Outline Stroke, etc.

I guess they'd need custom icons - maybe they could use user-defined text labels or acronyms (eg: SSA) as a quick default, and you could allow users to also create their own icons for use.