Here in MN, you can usually get away with hanging a red flag if your trailer load extends farther out than 3 feet. However, I trailer quite a bit at night and didn't want some one to tailgate me at night thinking that the TI only extended out to the rear trailer lights. So I replaced the front trailer tongue tube with a longer section, moved the front hull roller forward, and adjusted the TI cradle positions and added rear rollers. That way the rear of the TI extends only 6 inches behind the lights and the front and rear of the hull have some support. I adjusted the rollers to just touch the bottom of the hull. Several Forum members had mentioned that the TI hull wanted to slowly sag on the ends during the summer if it sat only supported by the cradles. The rollers prevent any end sag but don't exert upward pressure on the hull.
Hobie assured me my that my new 2014 TI would be fine on the cradles on the Trailex SUT-350-AIT, but I'm interested in other users experiences - specially since mine will be stored in my garage in the Texas summer heat. I would prefer to leave it on the trailer, so am thinking that maybe a post/stand under the stern would be a good idea.
Alternatively, I like the idea of your trailer mod - can you post pics?