Backbone gives you lots of great ways to add variety: for example, randomised Pitch per hit, key-following of Pan, and so on.
I would like to see a modulator for Resynth’s Position or the Sample tab’s Start/End points.
I like to make claps and snares with added textures, such as splintering wood or ice. If this added texture is always the same it becomes robotic so I like it to change with every hit. Of course, I can do this via automation of Position but it’s a fiddly process. Yes, I could add randomised texture separately via a different sampler but I love the features inside Backbone so it would be nice to do it all there.
Just an LFO to govern the play head would be great. (I realise that Serum-esque LFOs everywhere for any parameter would disturb the purity of the UI!)