Is there a recommended ‘namespace’ for user-defined key commands? For instance, some combinations of modifiers that are reserved for this use? I never seem to be able to avoid iterating through a bunch of collisions before finally finding something halfway easy to remember and currently unbound.
Try Help > Key Commands. Opens a webpage so you can see what’s taken. And it’s even generated dynamically to include your current shortcuts.
In my experience, most commands involving Control on Mac are not used. Also, I use command + f, then any letter for filters (I mean, sequentially). Not sure if these have been overwritten in Dorico 4, since I didn’t have the time to try them out.