The problem is, you're misunderstanding the situation.
There is no such thing as "right foot" or "left foot" braking pedals.
Automatics have a big, horizontally arranged pedal, sitting in the exact center of the footwell that can be actuated by either foot. Moving either foot towards that pedal means you're already squeezing your legs together. (and again, best practice in an emergency is to have both feet on it!)
Your suggestion is basically: "If you're going to tell people to use chopsticks with their left hand, tell them to use left hand chopsticks."
I
don't LFB because I learned RFB. But if you practice LFB and LFB only, there is no practical issue at all.
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I do feel that advocating LFB or at least instilling the instinct to two-foot brake can lessen the number of these incidents. Simply moving your left foot over to the brake will already tell you if your right foot is on the correct pedal.