I agree with Rustyspoon#
![[Linked Image from i.imgur.com]](https://i.imgur.com/xuJ63zn.png)
Starting with your
General foundation:
YES (should be 3 "lite/med dark/Dark" and at the same time, good contrast) Dark mode (BB is killing my eyes) Yes (See Image)
Design around core functions (Chords View, Track View, MIDI View, Score View, Library (Browser) Yes Graphics that look sharp on resolutions of HD to 2k (graphics are too low resolution and are fuzzy on High DPI systems)
Support High DPI scaling mode) YES User experience where they only have what they use, and when they need it on the screen. YES 100% consistency of all mouse and global attributesNow we are talking. +1 Often when I show a conceptual block diagram, people tune out.
The best we could hope is agreement on the basics.
Light/Dark themes yes, much of BB is configurable in terms of color but the basic MS window framework will not follow the OS settings. I discussed this with Peter and even showed him the code and the current development tool that he is using but was resistant as it would have to be done a different way for the Mac. I have yet to get any one here to take it seriously. So, we will see.
Floating Transport sure why not. (thus, my kidding with Rusty)
The bottom line on that topic is to take it more seriously showing states and give it more room for things like Current Bar/beats counter etc.
Ironically since we seem to be thinking alike, I agree with your conceptual diagram 95%. I'm an advocate for toolbars being very configurable. I don't need a save button.

The buttons on the vertical bar represent the major views and all else I'm in support of.