I raced this way, three on the wire, on New Years Day in San Diego 2006. I am big, 250+, and I was sailing with two small girls, less than 100 each. The New Years Day Race is notorious for being light wind, but I had hope. By the end of the race, we were sailing upwind, triple trapped, passing big expensive boats with ten or more people on the rail, all the time, my crew of two singing silly songs and laughing. I was approached at San Diego Yacht club after the race by the skipper of one of the 45 footers that we passed. He said seeing my crew laughing and singing made his day. He was back in the pack, pissed and he said seeing them put the whole day back into perspective.
The two problems you may have, pitchpoling, even up wind as the leeward hull will have to offset your added leverage, and breaking the bow off the boat with the added leverage you will be placing higher loads on the boat, especially the bow just forward of the crossbar. There is also additional load on the rudders. Even with extended use of two big guys on the wire can fatigue and fail the 20's rudders. I am on my third set. So the two problems you may see are pitchpoling and breaking stuff, but you will have fun as you fly down the water between times spent swimming.
