@BlakeRichardson @Julian96
(Sorry Blake, i posted this then saw that you did clarify for another brand of AP. I haven't had my Mtn Dew yet today 😉)
It is possible. If you have one AP wired to the network it can act as a gateway for repeater APs within range. I just set this up with some test hardware. I had one MR set up and wired to the network and then up a second one wired as well to download the config and update firmware (it was in storage for a bit). Then I removed the LAN cable and just had it running off the power cord. After a few minutes it found the other AP wired to the network and formed a mesh with it and is repeating the wireless signal.