I didn't have that issue but I ran Cat5e and I'm using older models still (AC LR and AC Lite). Just a small hole slightly away from where the actual connection is to allow some flex under the AP and it was OK. Other than trying to get the AP seated back onto the plastic mount. That's a faff every time, especially when I was new to UniFi I had to do a few factory resets directly on the AP. Always remember to remove from the controller first if you're changing it!

For that matter the POE switch can be anything also, basic POE switches from say TP Link are half the cost of something from Ubiquiti.