I've got numbers for the "sweet spot" or the recommended maximum print size for roller frames and static alums for 23x31 and they are as follows.
Roller frame, 23x31: 14" x 17"
Static alum, 23x31: 12" x 14"
Obviously the vast majority of print shops go larger and they do it all the time, I'm not saying it shouldn't be done. These numbers are obviously not my own, they are from several sources and from guys who have done the work of figuring this stuff out so those numbers weren't pulled out of a hat. If you stay within the sweet spot mentioned above you will have better results across the board. It's not my opinion, it's just a fact. Most of the time you'll likely not notice the problems if you creep outside of the sweet spot, especially if it's only by less than an inch, and the problems will come about the further you try to stretch the limits of those screens. We will often times do adult and youth sized prints for a job and also be able to fit them both on one screen (so you don't have the excuse that one screen is better/worse than the other) and the youth print, 100% of the time, sets up quicker and prints better. There are myriad issues that CAN arise (doesn't mean they will, but the probability increases significantly) and you'll see registration issues and varying degrees of ink deposits across the print. When pairing the oversized print with a squeegee blade that isn't wide enough you start to see all kinds of strange problems.