I don't believe there are many (any?) professional archers in this forum, so the only ones we have to please are ourselves. I would consider it incredibly rude to offer another shooter advice, particularly in a tournament, that was unasked for. Well....maybe if my buddy was shooting better than me in a tournament, I might offer him a little unsolicited advice to get him to thinking about something other than his shot, but all's fair in that situation, right?
So I would never try to change anyone's mind about how he should shoot, particularly if he is happy shooting the way he already is. However, if a person feels like he isn't getting any better, and wants to get better, then he should realize that it is highly unlikely that he will immediately improve when he changes something. After I attended Rick Welch's class, I decided I wanted to shoot with a 2 second hold. Everything that everyone says is true: at first, you wonder what the point is and it seems like you're just wasting your time holding while you're doing nothing. And for a while, your shooting gets worse because you lose concentration and begin to creep during the hold. But after I learned to overcome those two problems, my shooting got better. It took a good year before I could maintain my concentration during the hold and avoid creeping with any consistency. For me it was worth it. YMMV, of course.