High CPU usage on macOS using COffscreenContext

After full days of optimizations and verifying that my UI is only updating the correct views, I’m still making no progress on this.

I’m trying to set a breakpoint in VSTGUI_NSView_drawRect from nsviewframe.mm to see what is actually being drawn by the system, but xcode refuses to break there. Any ideas how I can verify what rectangle the system is actually drawing?