Note that for Unifi, the “Auto” power setting actually means Full Power. That is, unless they changed it in the past few months as I haven’t checked the UBNT forums recently. Most recommendations around the forum are actually to set the AP power to Low. In my case, I have all my three APs set to Low for 2.4 and Medium for 5. I used to blast 5 at Full power everywhere but I lowered it to make roaming better. 2.4 has always been at Low to minimize RFI. Even at these settings, if, for example, my Master Bedroom AP goes down (because I’m rebooting it or doing a firmware upgrade) all my devices are still able to roam into the downstairs AP with no issue. For reference, I live in a 110 SQM split level condo with cement walls.