I think it’d be great if we could save individual parts as a preset. Like if you like the layering a few kicks, you’d save it as a kick drum preset that you can load up from “Add Another Instrument” or “replace stack” (or whatever the options actually are). It could have a pop-up to ask how you want everything routed if there are any routing changes from when you first saved that preset. For auditioning a preset, maybe the program could export a hit at a certain velocity as a file so that all audition samples are of the same velocity or something and you can hear it before loading. Not sure how feasible, but if it could be made to work it could be a game changer
As an additional request, give us midi packs based solely on drum fills. I like to write my own drum parts, but fills are usually a struggle point for me