Eyyo,
probably impossible, but here goes. I have a bunch of idea song files just consisting of a couple of patterns, which are fun to loop and play around with muting and solo’ing through (left/right)mouse clicking in the scopes. Trying to get a feel for the eventual arrangement, when parts should kick in or not. The quickness to create some kind of performance is great imo.
Could it be possible to create a tool which will record this (perhaps through inserting the X’s in the matrix blocks, creating volume automation and/or inserting volume pattern commands) and while the tool is enabled; will auto grow the songfile with the new patterns? Similar to how the autoclone pattern tool (Auto Clone Patterns | Renoise) will automatically grow the song when a sequence slot is selected and the tool is enabled.
I bet through workarounds, setting up and midi mapping a similar workflow can be achieved recording through a midi controller, but the right mouse clicking in the scopes feels so quick and instant, I think it would be great to be able to record these actions 
.
If scope changes are impossible to fetch in lua, how about the “M” & “S” icons in the mixer?
If there is a tool which can do something similar let me know!