I can see that. Been in a few of those rooms that do resemble multicolored bird nests.
I would expect that since most of these rooms only admit authorized personnel, the safety requirements would probably be limited to training the technicians about the stored energy and how to isolate it when necessary.
There may be concerns about ventilation since charging batteries generate hydrogen gas, but most of the large UPS I have worked with have sealed batteries and were in well ventilated rooms.
I never knew one to generate enough noise to cause problems with PLC power supplies, but ours were producing 120vac which would then get filtered by the PLC power supplies that were connected to them. I would be a bit concerned about the thing getting forgotten, beeping for no one to hear for a few minutes or hours, then falling on its face. Then everything hooked up to it goes dead all at once. This happened at a previous employer once, but we did not service it ourselves, there was a bypass mechanism to get the plant running while the UPS was down, and we had the contracted service company in there right away to take care of it.