Ah, the SIP requirement for yabai isn’t that important IMO. They detail it in their wiki [1]. Incidentally, I tried it out since making the comment, and even without SIP disabled I’ve got it close to where I want it to be. It’s still not as great as my custom i3 setup was, but a few more weekends might get it to a much more comfortable place.

1: https://github.com/koekeishiya/yabai/wiki/Disabling-System-I...