I've thought up some possible improvements for Pro-Q:
Have a small palette of EQ styles that have slightly different EQ curves (perhaps based on analog hardware) that you wouldn’t be able to create using different slope and Q values.
Also, have the option of selecting a different style for each band.
Like SurferEQ by Sound Radix, be able to automatically adjust the frequency (or another parameter) by the pitch of the source (or another source via the side chain). For example, I’d like my high-pass frequency to increase when my vocalist moves to a higher register thus removing more unwanted background noise or bleed. (This is kinda possible in Pro-MB, but not in the same way)
Have a 6-step knob for all the different slopes (or even continuously variable) rather than a dropdown menu. Only a single click would then be needed rather than two.
Again, have a knob for the display range size rather than a dropdown menu (perhaps a vertical looking bar like Pro-L's gain knob?). Might also be good to have a more automatic adjustment that follows the amount of gain you're using.
Have the option of selecting a different type of processing mode (zero latency, linear phase…) for each band. In linear phase for example, only some bands may be causing audible pre-ringing, so it might be good to be able to change the processing mode on those bands only, leaving the other bands untouched.