A lot of relay boxes will both detect the switch position and toggle the power, so you should be able to get rid of all smart plugs that you were planning to use for this light.

The relay should have these connections:

• Live input from breaker box
• Neutral (both from breaker box and to socket)
• Switched live output to socket
• Connection to one side of the manual switch
• Connection to the other side of the manual switch

You may have better luck with a smart zigbee switch to replace the switch. Be careful that it complies with your local regulations etc.

If you want the aesthetic of the current switch, you can alternatively get relay modules which would sit in the box behind the switch and connect both to the switch and the socket.

If you don’t want to mess with the in wall wiring, you can get covers that sit over a wall switch and contain/mount a battery smart switch.

If none of that suits, sounds like you’re on the right track with powering the light from a non switched socket and using the presence/absence of a second device to identify the switch position. But I don’t have advice on the fine details.

If I’m understanding correctly, this is saying that isolation between different clients on the same VLAN is broken? But this attack doesn’t break isolation between VLANs?

So the major issue is if you’ve got a guest network on the same VLAN as your main network

We (uk scout group) use g suite or whatever they call it these days. The Google connection isn’t ideal, but we get it completely free, the t&cs and level of control over it are a lot better than consumer gmail/drive, the learning curve for techphobic users is about as shallow as possible, and we don’t have to spend volunteer time on maintaining the platform. So definitely worth it for us but your situation may vary.