Tbh the architecture is already in S1 if you load 16 samplers(which could be 16 pads on Impact)and (still assigned to midi) they will all show their own notes in the piano roll layered on top of each other so it's easy to see each note from all samplers making all editing per note, instead of what we have now not being able to polyphonically pitch each note in Impact.
Patterns are the best option imo because it's already possible to switch from piano roll to step sequencer. All we need is each Impact pad to have their own piano roll and be able to see ghost notes from all midi and we could have multiple pitches on the same pad hits. The step sequencer could then have a phrase mode allowing us to hit a pad that plays the notes in the step sequencer for that pad only. For example: hitting one pad in phrase mode would trigger a snare roll. Actually, each pad needs to have the ability to be triggered from the step sequencer as a regular step note or phrase giving you maximum flexibility.