For fullscreen windows I also added a custom implementation with super + f that works in the workspaces setting. Just making videos fullscreen or clicking the green fullscreen button still exits the setup to macos fullscreen. The system is still kinda usable with mac fullscreen in parallel but its not a clean experience.
There is macwmfx: https://github.com/aspauldingcode/macwmfx
I use it on a couple specific apps to remove title bars. You can inject it with DYLD_INSERT_LIBRARIES.
MacOS is so absolutely terrible for programming work. The only coder-favorable unit on Mac that I wish Linux had a similar alternative for is the OSA layer. Nothing else is justifiable there from a software engineering standpoint. Nothing.
Apple keeps insisting on Jony Ive's influence and keeps making "an operating system for florists". Well, I'm a damn programmer - I need the utility, I don't care about stupid animations, widgets, jumping icons in the Dock, etc. If my enterprise overlords didn't push it so hard down my throat, I would be so much happier just using Linux.