I normally run with z-lift set at zero, but this does on occasion cause visible drag marks. It would be nice to have an option to have z-lift occur on retraction only when the next travel move is going to occur over any topmost surface.
You can still do it with separate processes, you will just need a bunch of them. But I agree that it would be finicky and I think S3D needs a better way of managing processes. I want to be able to duplicate, clone, and drag-and-drop processes like layers in Photoshop. E.g. Clone a process, lock all of it's properties to the process below but override property D.