I really like that idea. A lot of positives to it. It would give me a ton of space too, of course. Noisy VFD would be out of the way and rewiring would be minimal.
For now, I drilled a hole. It's in a good position right in the middle of the ventillation area under the control box. I can bring the ethernet cable through that hole and right into the Acorn as it is propped up off the metal mounting plate with brass spacers. The board can go more toward the drives because most of the outputs that would have been blocked are in the DB25 breakout board.
Did some bench testing and getting motors hooked up and running, so I want to get the board in a place where I can also get all the basic I/O working.
Thanks for the 'out of the box' idea @nigelo !
EDIT: If I were going to do this again, I would use a 'left angle' shielded RJ45 connector:
https://a.co/d/bma2kCB