that looks great. +1
How to differentiate long notes short percussion notes?I do not know if this would be simple to build.In theory, the note OFF would serve to change the background, but the note OFF is used for other purposes as well.Some time ago we talked about using blocks of colors.In Renoise I think there is no relationship between the background and the written notes.Some specific code would have to be devised.
I think the border issue is feasible. But changing the points according to the notes is a different theme.But it gives me the feeling that all these topics end up forgotten in the forums.