My Ubiquiti UniFi UDM is not good at device identification. It's kind of annoying because I have this big list of devices on the network and it's peppered with devices that I know don't exist. I'd appreciate it if it said something like "Maybe iPad Air", instead of just "iPad Pro 2nd Gen" when I know no such device is on my network.
No it isn’t, vendor prefixes are sort of an anachronism. Bit 41 - bit 1 of the first octet is reserved for local (random) use. That and the group bit (40) set to 0 means the second digit of the human readable MAC is 2, 6, A or E, but that’s it.
On the same WiFi network yes you can - it uses the same MAC on the same SSID. Remembers the "random" MAC after the first connection (and if you first connected to the networks before they added MAC randomisation in iOS14, it "remembers" the actual MAC of the device, so you didn't have compatability issues after the iOS14 upgrade).
So you can't use it to track devices between multiple SSIDs including when scanning for networks, but you can use it to persistently identify a device when connected to the same network.
I found out that unifi plug in doorbell chimes use an esp32 this way because I saw one on my devices table, before it had booted fully and handshook as it's real Identity
Do you mean the non-PoE version? I have the PoE version sitting in a box somewhere and I'm a ESP32 enthusiast so I'm wondering if that's what I'll be doing today. Surely they're using it just as a WiFi coprocessor? Or...?