Mate they look like a top idea to me. I just recently got an old 3.7 metre Quintrex back in the water and realized that when carrying a few on board it is very important to keep the weight distributed evenly in a tinnie both on the plane and whilst sitting off the plane while fishing. I started thinking of the outrigger canoe idea and how to increase stability using a similar idea and then up pops your post. Definitely something I would consider because I like fishing in the bay. If you decide to get them then let me know how they go. My only concern would be the fact that when fishing you always bring your fish in via the side of the boat so it wouldn't be too hard to either have a fish spike go through the air-o-float of even a hook. If they had similar attachments using styrofoam I would probably even consider it myself.
Poodroo