What about just using the nmap homeassistant plugin, which doesn't require any kind of client device setup? Assuming you use wifi at home, and your phones automatically connect, and your wifi isn't too spotty.
Can also use a router integration. I have a mikrotik and it tracks DHCP clients which I use for presence detection using a bayesian sensor
Yup, I have HA setup with Unifi integration and it works perfectly for detecting if wifi clients. It gets alerted immediately upon connection (so I don't think it's polling the controller), and they get marked as away exactly 2 minutes after wifi disconnect.