It's not a perfect replacement for mouse-focus, but most Mac apps can be interacted with without bringing them to the foreground by holding down command before

It's not a perfect replacement for mouse-focus, but most Mac apps can be interacted with without bringing them to the foreground by holding down command before clicking on the inactive window's controls. Also, right-clicking usually won't surface windows. Won't allow you to type but it's good enough for pasting bits in terminal windows, toggling settings, etc without changing which app or window is frontmost.