> On a Mac with Emacs 25.3 with focus-follows-mouse and
> mouse-autoselect-window both set true, I get inconsistent behavior.
Beware: `focus-follows-mouse` is a variable which does not *cause* the
focus to follow the mouse. Instead it has no other effect than to
inform Emacs that it's running in an environment where the
window-manager (or equivalent) uses the policy that the focus should
follow the mouse.
Stefan