You’re right the Show Notes support in Cantabile is somewhat limited, but that’s partly be design and partly because I wanted to collect together as much as feedback as possible for building anything more. Unforuntately I still don’t have a clear idea in my head on exactly what this should be.
Yes, I do have plans to improve show notes down the track. It won’t however be a full score reader - there are other apps better suited for this and I think this is outside Cantabile’s wheelhouse.
At this stage I’d prefer focus on better integration with external tools in this area. I know some users already control external PDF readers by using bindings to invoke external programs - that’s probably the best place to start.
As for further customization of the main screen for custom controls etc… please see this post.
Brad