It would be nice if you were able to hide specific tracks/groups from the track scopes. Sometimes tracks are just placeholders or scribbles that needn’t clutter the scope if this was optional.
renoise.song().tracks[1].scope_visible = false
and perhaps “Toggle scope” in the pattern editor context menu.
Thanks for considering 
+1
I would indeed use this if I understand correctly. Sometimes I write something with an instrument or fx and render it to a new track, and keep the original for reference or later use. To clear this space would be really helpful.
I really, really would love to see this feature as well. I use so many sounds and instruments and create own track for each one of them in case I need to add some effects to them later. This becomes unmanageable mess very quickly as the song gets longer. Thankfully it is possible to assign specific effects to instruments now, so that makes life a little bit easier.
The hiding effect could be similar to the one seen in the effect panel, so it would not hide the track totally but rather minimize it. Going few giant steps further, it would be cool if tracks could be assigned to be hidden for specific patterns. This way the hiding would be automatic depending on which part of the song you are working. For example, intro of a song could have 4 tracks specifically in use for the intro, but for the rest of the song they’d serve no purpose. As you would move patterns down past the intro section, those intro tracks would get automatically hidden, etc.
This tool might not be exactly what you propose, but you might find it useful when dealing with lots of tracks. It automatically expands/collapses tracks when changing sequence, depending on if they’re empty or not.
“Auto-collapse empty tracks” in the pattern editor context menu.
https://forum.renoise.com/t/new-tool-2-8-collapse-empty-tracks/34553
This is exactly what I was looking for! The automatic option to hide empty tracks per pattern is actually more flexible and better idea. Thanks for creating and sharing this tool!