Matt,
You might want to talk to Sail Newport.
http://www.sailnewport.org/npt/m/_general/default.asp
We raced F18HT's for 2 years in the Newport Regatta in a division with j22, Fireballs, Sheilds and the Star class. We had our own start and never had any issues. In fact the race committee for our division was able to get the multihulls on a few more races because we were back and ready and they weaved us into the start sequence while the leaners were out on the course.

North Barrington YC (RI) was the race committee for our division. I'm sure that if you call Sail Newport they could put you in touch with someone from North Barrington YC and you could ask your particular questions.

My memory of the races was that the course was spread out enough that we never had any issues.

Another race I did with big monohulls was a round Jamestown race and they started everyone together. Being on the line with those giants was scary (40-66ft) It was windy and they were all leaned over hard, sailing back and forth across the line during the starting sequence. Being down at water level gives you a very unique perspective on a big monohull, especially when they are bow down, leaned over. They look very fat from that angle, and you cant really see anyone, the only thing you see is the bow, the keel and the side of the hull. The people are very far away and the boats seem really big and threatening. I remember Peter Johnstone sailing up to me and saying "you might want to stay out of the way, getting run over by one of those would be a bad day to die.