It appears to me that there are a lot of requests to provide conditional control in different contexts : follow actions, deactivating widgets, holding MIDI messages, etc.

I find that a rather elegant and simple solution to all these use cases would be simply to add a single condition action that, if met, will just not execute the actions that follows. You can then insert it after the mandatory actions to simply prevent a list of actions to be performed, for instance : pressing a button, I always select a given preset, but I only mute the source A if the source B isn't muted. You would have the following sequence : 1 - select preset, 2 - condition source B not muted, 3 - mute source A.

The condition itself could be based on a lot of things : parameter value equals / not equals/ greater than a fixed value (or another paramete value ?), state of a widget or a source, etc. But once you have the basic action you can keep adding more complex conditions as needed, it won't affect the rest of the actions and won't clutter the different menus.