Support for TP-Link Deco M9 Router Integration

I’m just looking to get device connection status out of the M9 router when my in laws come over to see if their phones are connected to the wifi - this way the lights don’t turn off on them when me and my wife leave the house while they’re watching the kids. I do not want to install the Home Asssistant app on their phones. The only two options I can come up with:

1- Use the TPlink “automations” part of the Deco app to turn a TPLink outlet on when one of their devices connects to the wifi. I can buy a TPLink/Kasa outlet for $10, so not much investment. I wouldn’t plan to even plug anything into it but the status of the outlet would be visible in Home Assistant and I can run automations from it based on the outlet being on or off

2- Use the TPLINK router applet in IFTTT which I’m paying the $2 a month for anyway to create an automation that sends a webhook based on their device connecting/disconnecting

Neither way seems ideal - any other ideas? They both have Iphones so from what I see status based on ping isn’t an option. I really like the M9 router’s range and performance, but I’m hugely turned off by its lack of configuration options, and the fact even its limited configuration are based on a cloud connected mobile app. The Mobile App sucks too and isn’t even intuitive with where the config options are. Connecting to the routers local homepage through a browser is even more of a joke with its limited settings. I keep seeing new firmware is coming, but not holding my breath.