Was never fond of the idea of a Piano Roll inside Renoise, but as you've done it anyway, and others are liking the idea, here's a suggestion (an important one).
Go vertical ... I mean why are you using a horizontal scroller when Renoise is vertical by design?
Just because other DAW's do it that way doesn't mean you have to use the same bad design. Be inventive and make it 'belong' Renoise by making it a vertical Piano Roll to match the vertical tracker aspect of Renoise. Making it a vertical Piano Roll is not only better from a design integration aspect, it's simply better by design cause it's the right way up! Think about it, those horizontal Piano Rolls in the other DAWs are wrong, they are all wrong, because they all suffer from having the keyboard displayed on it's side. Make a vertical Piano Roll, however, and that nonsese is removed cause it means you can have the keyboard the right way up, positioned at the bottom of the Piano Roll where it should be. It means you can line-up the notes scrolling from the top of all the keys, black or white, and all the right way up!
So personally, congrats and well done on for what you've achieved, but zero points for making the same mistake they all make.
Renoise is vertical by design, so it makes sense to take advantage of that and have a superior vertical Piano Roll.