Add a button to submit usage information
This may be a crazy idea, and I'm not quite sure of the consequences. But could it be possible to include a button or menu item somewhere allowing users to submit some sort of usage survey or poll? It would use a similar platform as the Feedback button, but requesting more detailed information such as type of music, typical instrumentation, number of measures, use of the edited scores (publication, study, rehearsal, performance), number of scores per year, etc. It could also request opinions on current or upcoming development projects or proposals (so it doesn't need to be a static survey).
This could provide valuable information on future development priorities, statistics and more.