[stavros]

Zigbee is great, but my chair has a mesh :/ I'll see if I can print something below, so that the sensor is activated, but yes, it does seem that it would be pretty finicky...

[rpgwaiter]

You can buy the sensors they use in car seats for like $10 https://a.co/d/0dibAFxc

[transpute]

Ceiling sensor is another option.

[stavros]

For now I've put a mmWave sensor under my desk, which works fairly OK. It's not perfect, but definitely good enough.