It would be nice to have the option of specifying change in processes by layer number. I mostly use start/stop for changing fill specifications... specifically concentric on the first layer only and then reverting to rectilinear for the balance. As it stands, I need to specify the start/stop in mm, which requires a change any time I change the z height. But all I really need/want to do is say, "print the first layer with this fill pattern no matter what the z resolution is"
Of course this would also greatly benefit from a preview mode that told me what layer number I was currently looking at. Or if not the layer number, at least the height in mm. It's hard to customize processes by height without that kind of feedback... others have asked for this feature already, but it doesn't seem to have gained any traction with the developers. <sigh>