Okay, here we are a month later and it is time for an update. I was reading through this wondering about the brace function as well. After removing it top and bottom from a 20g tall that was sitting in someone's yard I realized it cannot be purely decorative? I mean it was hell to remove and I have battle scars to prove it. Sure if the tank fails the plastic rim can snap but this tank was sitting out in someone's yard under a tree for years and I was cursing a storm removing that plastic.
As much as I would like to trust removing the rim off my 20g L or the 50g I am picking up this week, it still is in the back of my head that I can come home one afternoon after removing the rim and a mess is waiting for me. Tempted but man you really have to think carefully right? I like Roundar's glass center brace though. Not taking away from the look of the tank and not obvious too.
Insofar as how to deal with a glass lid when you have no rim..