I have considered this also.
I've enjoyed my Hopkins "Pro Line" 6-4 and done some minor upgrades. My 23X31's will actually fit the back clamps, but the arms on the carousel seem so short, given that I have 16X18 Shirtboards. It seems like there is nowhere to stop.
New Shirtboards probably, Springs are too weak, side clamps....maybe it's just too much. That's why I've been hesitant.
But this old press holds registration and could probably spin for decades to come. Even with the auto, I still find myself setting up 24pc, one color jobs on the Hopkins. Setup and cleanup is faster, but that is gradually changing.