With the x32 plugged into a windows, mac, or linux based pc, there's a program called "X32 Edit" you can download from behringer's website, that allows for control over the x32 via a personal computer. There are likely x32 drivers required as well. If anybody owns a Raspberry Pi 3 there's an app for it as well.
when you run it, you get this
You click "Routing" and this window pops up, and you click "ultranet" and this is where you configure the p-16, which again, is the only reason the x32 has a cat5e port labeled "Ultranet" on the back of it.
This effects NOTHING else in the setup, and allows anybody who plugs a p-16M into the ultranet port or into the ultranet out from your p-16m control over what they hear in their own headphone mix. The channel assignments will be the same, but each p-16 has it's own volume settings per channel.
Hold off on returning it imo.. I'd show your engineer this post and tell him to make it work. Trust me, you'll enjoy the benefits. He seems to be misinformed.
The alternative is to set it up within the menus of the x32 itself, which still does the same thing, it's just not as easy to configure.
The only way what he's saying makes any sense is if he's already using the ultranet port, which makes no sense to me as why anybody would do so other than to add personal monitor mixers designed for the x32 system.
I never have to even leave my spot in the jamspace to adjust any given aspect of my monitor mix, much less ask anybody else to. My P-16's sitting right on my mic stand. Used a piece of tape plus a pen to label the channels.