I’m saying everything I said as someone who has worked with glass every day for 15 years. glass is my job.It is a huge risk, with a lot of unknowns. One of the issues I faced when I was building the tank out was that I couldn't find who built the tank to ask questions. It does seem over built, but without being able to speak with whoever built it, I don't have insight into the logic they applied when the were building. The glass is fairly soft, so I believe cutting a hole in those panels is possible, but the how and the risks being question marks is a lot to try to process. Ultimately, I'll probably upgrade the lights, and hope for the best. Maybe when I break this tank down for an upgrade, I'll try to cut then, and do testing with less risk. Or not. No idea.
the chances of it failing when you cut/drill it are very high.
persobally I’d just go get another 90G tank, they are a dime a dozen, and Then you wouldn’t be kept up at night wondering when its going to fail