A good friend of mine has done a couple of serious boat restorations and is fanatical over his maintenance program (...and is even more detail oriented than me

). He likes to say that when his boat is in the water for the season all it is trying to do is sink the whole time, and it is his job to make sure that it doesn't.
Same thing with these campers. When they get wet they are trying to leak, and it is our job to see that they don't.
You are doing a great job and I think if more people were comfortable doing good quality glass work we would see a lot more campers with molded corners.
One of the deciding factors for me doing a foamie was the omission of the trim and all of the screws that go with it.

My MaxxAir fan mounting ring wouldn't really lend itself to that kind of modification because of the way the fan mounts to the ring and the way the interior trim fits up inside. You could maybe do it with double ended studs
like these (or whichever size you need), giving you the opportunity to set them in epoxy, then maybe use acorn nuts and sealant on the top side. Not sure it is worth the trouble though, as more things could go wrong (...like misalignment making it hard to get the flange on).