This idea came as a solution to practical problems I encountered while using renoise, there is no easy way to have sets of cueable patterns, so if you have say a 6 minutes track you may have the same couple pattern repeating dozens of times.
The solution comes in the form of having a way to associate some tracks to “special timelines” in the pattern matrix. These special timelines could be called with a command from the main timeline the commands should have these options:
-Cue a specific pattern and play it once
-Cue a specific pattern and set it on repeat
-Cue a specific timeline and play it all the way through
-Cue a specific timeline and play it all the way through then repeat it
If it is easier for the devs, these secondary timelines could always be in sync with the main timeline (as in line 9 always plays at the same time on all currenctly active timelines).
Not only this would allow to have somewhat complex activation of sub-themes within a whole song but would allow for much faster composing for people who use midi keyboards for the melodic tracks.