Do not update to iPad OS 13!
Just wanted to shout this out as it's known right now in iPad music community.
Multitouch (not just music apps) is broken in iPadOS betas.
You won't be able to successfully do anything with 3 fingers.
This includes notes and/or pads, soloing, muting, volume, macros, etc.
Undo/Redo in unaffected in BM3. Can't say this for other apps.