I never realized this because I read owner's manuals for stuff like maintenance schedules and vehicle features, not cover to cover, but I was surprised to find that some owner's manuals I'm looking at warn to not rely on the P setting and always engage the parking brake, even on level ground.

I was never taught this, and consequently me and everyone I know with auto cars never did it. Moot point for me as I own a manual now, but do you Opponauts with autos or anyone you know actually use the parking brake, or is the P setting good enough?