I’ve never used network manager on a server and don’t understand your routing configuration, im assuming you have wg0 configured to have a default route (ip route list).

You should be able to connect a docker network to the vpn by using a macvlan insted of a bridge type network and set the parent interface of it to the wg0 interface.

docker network create -d macvlan \ --subnet=<internal vpn network>/24 \ --gateway=<gateway ip> \ -o parent=wg0 vpn-net

modified from the docker documentation

Probably also set an ip-range on the network to make the auto assigned ips not conflict with other wireguard nodes (see linked documentation).

Make sure the allowed ips in the wireguard configs are set correctly.

You can also do ipv6 like this, see the end of the linked documentation page.

It shouldn’t even be able to run it, because the x permission bit is missing. As far as I know binaries can’t include icons on linux, so it would look different too.

Voltage drop probably isn’t a problem here, because your sensor draws verry little power. If you can get POE for cheap then thats a better option.

You could get a cheap usb a to c 2.0 cable, cut it and extend the wires with some 4 conductor J-YStY cable or what ever is common where you live. The sensor probably doesnt use enough power to cause a significant voltage drop.