It would be very handy to have a transform (change) history (e.g. undo history) for any element in SO, be it track, effect, etc. If you are familiar with software version controls, specifically git, the idea would be similar but stored within the song's project files. The idea is that for any given element in a song, be it a fader, single event, full track, etc, you can see the history of that single element and revert/undo to any point in that history without affecting any other part of the song/project.
These histories should also be saved an accessible for the entire life of the song, persist across saves and restarts, etc.
Would also be handy to be able to export these histories as macros or similar so they may be imported in other songs and applied.