Using GLD80 or SQ6 as a monitor board

Hi all.
I’m thinking of buying another desk. I currently have a GLD80 that I bought when they first came out. So I would like a back up desk around this price point.
I could buy another GLD80 or get the SQ6. I would then have 2 desks when I have 2 jobs on at once. What I would like to do is also use one of the desks on stage as a monitor board on some of the bigger outdoor festival work. So my questions is to anyone that knows. Can I run the GLD80 at front of house, I presume with an ACE card in it. Then from the monitor out on the AR2412 into either a GLD80 or SQ6 with I presume another ACE card in the desk on stage as a monitor desk? Set the pre amp gains from GLD80 at F.O.H and then use the digital trim to fine tune from stage monitor desk. So will either of those desks work as a monitor board with the ACE card inserted? At present I have used Ipad on stage which is ok but a desk would be nice. I have also used another desk and done analog splits through a isolated splitter box, but I want to get away from all the clutter of wires everywhere. Just a single Cat5 cable from stagebox to monitor desk would be a dream.
Can anyone help or offer advise on what will work or not
Regards