I think most of the controversy around double clapping is how most new players do it anyways.
Like, I've been guilty of using a double grip instantly in the first few turns of Aikido matches before, but it was never straight up. I would try to transition from a punch or kick into a double grip to transition into a Takedown, throw, etc. - If that makes sense.
I wouldn't call it legit or a strategy, because most players who use it only use it solely for the purpose of attempting to end the match with the one opener. High level matches(at-least in my opinion) should be going off into free-form fighting, kicks, punches, etc that try to counter each other and eventually wait for someone to slip up. Either into a decap, dm, or dq.
But then there's the one-shot one-kill styles used in shorter matches like Taekkyon or something that are short because of the way the mod is.
That's just my '11 player opinion though and is probably not too relevant anymore.