Sadly Apple picked neither option. 3rd party apps cannot meaningfully interact with Spaces for example, even basic things like moving windows between spaces or adjusting the animation speed so it's not nauseating on ultrawides.
> even basic things like moving windows between spaces
I don't really use spaces but I've got "Displays have seperate spaces" turned on and Rectangle Pro has "Next Display" and "Previous Display" which moves the foreground app to, unsurprisingly, the next and previous display (which seems to be a space).
Are you after something like "move this window to space Y" rather than just "next space"?
You hit a keyboard shortcut, you get to the new space with 0 animation/transition. It can work with SIP on but only on macOS older than 10.14.
They mention here this is due to some changes they make to the Dock https://totalspaces.binaryage.com/sip-details I'm not sure if the only part I care about (instant Spaces switching) would continue to work without that / if you turn SIP back on. I haven't tried.
