I guess what you could gain in this scenario is forcing them over early, forcing them to tack, or putting them in irons right before the start. Trick would be to not go into irons yourself when attempting it. Imagine that, and the reputation you would gain if you perfected that technique!!!
Rules discussion aside, doing this is a very low percentage maneuver - meaning that it doesn't work more often than it does.
You're trying to fight through an area of really bad air, usually with not a whole lot of speed, and trying to force someone else to do something they really don't want to do - which means you aren't paying attention to driving the boat.
More often than not, you send them into irons (or worse, they inadvertently tack), you stall out and there's a huge pile-up of boats behind caused . . . by you. It's a way to become unpopular very fast.
This is especially bad in uni-rig boats that get into irons easily. There will be a nice orderly line of boats at very slow speed, more or less luffing before the start, everybody minding their business, when an inexperienced person will charge in, yelling, "UP! UP! UP" and because nobody can maneuver quickly, everybody ends up in irons. For a long time.
We had a kettle of tar and a bag of feathers ready for Peter Cogan when he did this at the 1996 Hobie 17 Continentals.
Yeah, I still remember it after 15 years.
