The color manipulation you have right now is powerful and opens up amazing possibilities. In working on my current nozzles in vox I had a few ideas to expand on that power.
Abstract nozzles. Right now I have a quad crane, so I get 4 nozzles as my machine setup in vox. Same with duel. Of course this makes sense. It would be powerful to abstract that a little bit, so that this initial setup is customizable with ‘virtual nozzles’. Within the current setup you could use them as a color in the same way. When selected and the virtual nozzle is encountered by the slicer it would pause the print and wait for a filament change.
Why? Right now there is a debate with the 4 color printing about whether / when one should setup for cmyk(black) or cmyw(hite). I plan on using both at times when its necessary. Or I could use a specialty filament for different areas of the print from 1 nozzle. This would open up other parts of the spectrum within a print without the need for more nozzles in the hardware.
Axis isolation - It is extraordinarily difficult to use the selection tools in a controlled manner within the viewing space. It would be nice to be able to use modifier keys (ctrl shift etc) to extend the selection across the print constrained in a certain axis. So for example I would select across the visible side, hold down ctrl and have that selection extend straight across parallel to the bed instead of the angle that is normally achieved. 1 key combo per axis x,y,z, would be nice, though a combo allowing diagonal might be useful as well.