Change playback template mid flow

I have a current flow that has halion sonic for orchestra and organ. Is there a way to change the type of organ in the middle of a flow that requires a reduced “registration” (small pipe organ for eg), then resumes the default organ later in the flow? I’ve read that you can change instruments in a flow, which is part of a project with multiple flows, but can’t find a way to indicate what I’m trying to do. I realize that you can “change instruments” midstream, eg., C trumpet to picc trumpet etc., but this is a bit clunky for organ works. In organ scores you indicate changes to the types of stops (registrations) along with other items like dynamics. If it’s not possible, then perhaps this might be a future addon.

A different issue: The only way I have found to list registrations at the beginning of a composition is to place it in the first page as text. Are there better ways to do this?