I have 1 Pi and 2 Odroid XU4. - Pi for Pi-hole - Odroid for VPN and home assistant server and also a CCTV. - Another Odroid XU4 for RetroPie games.

I think CO is more dangerous than CO2! Why not CO?

CH4 is also dangerous. It's a different problem. CH4 blows up your house and is very rare. CO kills you and is very rare. CO2 buildup causes mild issues (like headaches, sleepiness) but is very common.

I have been using Odroid XU4 for home server (home assistant), personal CCTV, controls IR blaster and other sensors for years, still running perfect without rebooting for months. I also have Pi 3 for Pi Hole, but honestly my Odroid XU4 is more stable than Pi 3.

Android app with Bluetooth/Wifi scanning ability needs Location permission to perform the task, that's GOOGLE policy. :/