Yes, keeping overview over zoomed out notes has also been my concern regarding this thread. Also I think to my preference it wouldn’t matter so much for the birds eye view concepts presented here. Those would indeed make sense when using phrases in a clip style composing. I was always thinking about micro timings and fast note progressions.
My Idea for this has once been…marking the small space between lines (maybe also backdropped expanding behind the lines above and below) with colors if there are zoomed out notes in between. You could just mark it like “here is something”, a concept I know from the now-dead Aldrin tracker (a buzz clone), it just colored lines that would contain notes that would be visible when zooming in.
It could even go further to enable some sort of striping or color coding so you roughly see what is going on in there. Alternatively in the same line of operation - as Backdrop a scaled down pattern with all notes and commands collapsed to color bars that won’t drop information.
It is all about you instantly seeing “yup, there is data between those lines I need to zoom in to see or edit” - not doing this would cause a lot of frustration tracking down those hidden notes ruining your song…