I just got a quote from Custom Aquariums too and thought the exact same thing. I was trying to cut some costs, by hoping not to purchase / make a new stand. My current stand is 1 x 3 oak top and is completely hollow in the middle. I don't want to put plywood on it, because it'll look dumb when you try to route a bullnose on it. Plus I don't want to see ugly foam on the bottom. I asked the same question about why a rimmed tank would need a foam support on the bottom, and they essentially wouldn't tell me why, just that they required it. I like the idea of their anodized aluminum frame, because it is cracking on my current plastic frame that is making me look into a new tank. Just put tempered glass on the bottom and call it a day. My AGA tank is tempered bottom with no supporting foam pad in the 19 years I've had it set up, and it's not the glass or silicon that's failing. It's the plastic rim.....