Thank you, that seems to be what’s happening here. I started looking into it and that’s what seems to be happening here: the system is forcing VSync by default and there’s some Quartz Debug tool that can disable VSync until restart:
https://www.reddit.com/r/geometrydash/comments/lx900l/macos_fps_bypass_download_links_in_comments/
That’s pretty lame that the system doesn’t let users customize this setting out of the box and per application.