Ok you're both right about the R button, but it's not like he's using this in the middle of a 7-13 character speed run so the time he achieves is still just the same as he would have gotten doing it the tedious way. I honestly don't see an issue here for the 1 character category.
He could have done it the regular way which would have taken twice as long but the end result would have been the same, a new WR. In fact those who are serious about this category should rather be embracing this method as it'll save you a lot of dead time.
How would you prove this? Also what to do for those that are prescribed these medications by a doctor, would those that for example medicate with amphetamines for ADHD not be allowed to speed run? If you were to prohibit their use you'll need a way to verify beyond a doubt that they have been taking these drugs and if so make sure that they were prescribed or obtained through illegal means.
You can ban whatever you want, but if it's not practical to enforce then there's no point to it.
I don't agree, in the end what's the difference between this and someone holding the R button? There's absolutely no competitive edge gained through this method.