Do I miss something? How do you adopt the device in the first place? If you have to SSH into the device and set the inform URL manually could't you just route the request based on the request hostname?
Every network I've set up (which is not many) has a dns search suffix handed out by dhcp. So the wap will resolve, e.g. unifi.branch.megacorp.net with zero config needed.
Yep, once you set-inform the host header handles the routing. This in particular is most useful for things like DHCP Option 43, where devices only get an IP.
We support two approaches, you can either pre-register MAC-Addresses or you can add source IP's to assist with that mapping. There is more information in our docs about this: https://tamarack.cloud/docs/migration
Every network I've set up (which is not many) has a dns search suffix handed out by dhcp. So the wap will resolve, e.g. unifi.branch.megacorp.net with zero config needed.