The "snap-on" plates have been around for YEARS.
They are pretty much the standard in other countries that use American style and size devices. Japan, Taiwan, Mexico, Colombia, Peru, Thailand....etc.
Even in South Korea, where round-pin European sockets are the norm, the switches and sockets are designed to fit in American-size boxes.
The only problem is sometimes they don't stand up very well to being removed and reused -- the little pastic "snaps" snap right off. Depends on the age and the plastic used, I guess.
