Learning a whole nother habit

Now that my car has AC I have to have the idle rpm a little higher.
Problem is when I shut the engine off it tends to “run on” for a few cylinder fires, which I really don’t like because it’s hard on cam gears and such.
(Especially when the engine kicks backwards)
I realize there is idle solenoids to raise the idle only when the AC is on, but I don’t really want to add another clutter to the carb.

I run an automatic trans, so now I’m changing old habits and shutting the engine off while still in gear.
It kills the engine immediately, and doesn’t hurt anything, but putting it in park before shutting down is a hard habit to break.