Okay, this is back to the original argument. No, if you gave someone who had never seen Stewart Lee, one of Stewart Lee's scripts, and asked them to perform it as a comedy, it is extremely unlikely they would perform it exactly as Stewart Lee performs it.
The first argument is, that doesn't necessarily mean it wouldn't be as funny. It would be different, but it might be hysterical. I'll grant you it's unlikely, but it's not impossible. You're free to imagine a case where it isn't funny, but I'm free to imagine a case where it is, because this is a hypothetical argument.
However, there's a second argument which is more important and more what you're getting at. If Stewart Lee was to enter a national scriptwriting competition, and he sent in one of his routines as a script, without any indication of how it should be performed, and relying on an extremely esoteric mode of delivery that he's honed over years of embittered personal struggle... he'd be an idiot, at least if he wanted to win the competition.
The brief of Sitcommission is very clear. You're writing for a cast who is not you, to be directed by someone who is not you, who you will have minimal contact with. To get to that stage you will first have been read in a pile of hundreds of other scripts. The way to give yourself the best possible chance therefore is to write something extremely clear, clean and easily understood on the first reading. None of which has to mean 'simple'. If your normal style is obscure and open to multiple interpretation, you're not going to do yourself any favours not changing your style for the competition.