They are designed to the same standard.
When it was said "you cannot break the aircraft with use of controls below Va" there was an expectation of reasonableness - or, if you prefer, good airmanship - in that sentence. Do something extreme - in ANY axis - and you'll end up with a nasty result.
All the FAR requirements for control inputs pretty much assume a single full application, and then the removal of that application. I don't believe any of the axes assume repeated reversals.