What is the problem?
You have to stop/pause a running session to be able to remove live recorded notes with undo and delete.
What should this feature achieve?
Enable Undo for patterns in running recording-mode, so you can reverse actions that was recorded into a track. [Maybe even the ability to jump between undo and redo]
Are there any workarounds?
N/A
Any links to related discussions?
Any references to other products?
SP404 MK2 → https://support.roland.com/hc/en-us/articles/4408181985179-SP-404MK2-What-data-is-deleted-when-I-use-the-UNDO-operation
You can already do this actually (it’s just not super obvious):
- While live recording, press
Rec twice.
- You move out of Live-Rec mode and are in the regular editing mode. Notice that the sound has not stopped
- Now you can edit the notes as you wish (including using undo/redo)
- Once you are done editing and want to jump back into Live-Rec, just hold
Rec + Play again. The sound should continue without interuption
Let me know if this helps or if you want to continue with this wish 
That works for me, thank you
As requested by the OP, we’re closing this wish as this functionality already works as described above.