It’s presumably to give you legal ground to sue if some corporation scrapes Lemmy content and uses it to train AI, or whatever other commercial purpose.
Hopefully if enough people do it they would consider the dataset too risky to use. They could try and parse out comments that have that license statement but if any get missed somehow they open themselves up to lawsuits.
That would force them to instead pay for content from somewhere that has a EULA forcing the users to hand over copyright regardless of what they put in their posts (i.e. Reddit).
The switches don’t have to control the lights they are wired to. I have Inovelli z-wave switches, and on these you can disable the relay. So the switch can still send out commands/scenes on the network but the relay is always on.
Then you would put in a relay unit in the electrical box of the lights or if you have enough room in with the switches. Then setup the switches to control their respective sets of lights.
Might even be a switch out there that lets you disconnect the relay from the buttons on the switch but still control the relay which would cut down on the device count.