Focus-follows-mouse, even sloppy, is problematic on macOS due to the menu bar. Moving the mouse up to the menu bar means covering space which can belong to a different window, which would change the meaning of the menu item when you got there.
"Focus-follows-mouse, even sloppy, is problematic on macOS due to the menu bar. Moving the mouse up to the menu bar means covering space which can belong to a different window, which would change the meaning of the menu item when you got there."
This is true, but easily surmountable.
Mondomouse, which is the last bona-fide focus-follows-mouse add-on that existed for OSX (circa snow leopard) had a switch timer that was user-definable.
So you could set the switch timer to .5 seconds or 1 second or something which would allow you to run the mouse across other windows without changing focus. That solved the menu bar problem that you are, correctly, pointing out.
I think it's also worth mentioning that if you're at the point where you're demanding FFM, you're probably already doing everything with hotkeys anyway so it's not like you're running up to the menu bar often ...
