I am sympathetic to the request for clarity on what works and what doesn’t in the Expression Maps dialog.
The options in the group that contains the ‘Transpose’ option are all as yet non-functional, except for ‘Transpose’, which is functional. The ‘Has exclusion group’ controls are non-functional. Otherwise, all of the controls in the dialog are functional: however, this is not in itself massively helpful information, as the real complexity comes in the way that the various playing techniques are actually generated and played back in the score. You cannot, for example, create expression maps for dynamics as you can in Cubase. The options for whether an expression should apply only to the current note or ongoing until a countermanding expression aren’t yet implemented. Dorico can’t currently make the connection between a playing technique you enter in the score, like a harmonic, and the durations of the notes underneath it in order to create the appropriate playback region. And so on.
I know this is very frustrating, because it’s hard to tell what works and what doesn’t. We are just as frustrated as you are about it: we are giving work on the playback side of the program a very high priority, but there is still a limit to what we can achieve. We have added so much useful functionality on the playback side of the application recently (NotePerformer support, video, MIDI automation, swing, etc. etc. etc.) and there is more to come, but at the moment, for example, I can tell you that working on real-time input from a MIDI keyboard has a higher priority than working on the expression maps side of the program. It’s easy for me to ask for patience, and I understand that you are paying customers who want and need functionality that doesn’t yet exist, but I hope you can see that we are at least not sitting around twiddling our thumbs, and even if you may not agree with every one of our prioritisation decisions, we are working hard to add features as quickly as we can while still doing a good job.
Regarding a list of features to vote on, here is a simple and short answer: no.