Hey not sure if you're still having trouble with this or not. I don't know too much about this stuff but I downloaded the docker qbittorrentvpn. Got it working with nord pretty quickly no issues and if it ever breaks connection with nord I believe it disables all connections until a connection with a vpn is found.
I used a youtube tutorial and adjusted all the settings such as paths, ports and things like that during the docker install.
I used this Tutorial to get everything working. Hope this helps. I know it might not exactly be what you're looking for as it seems you're routing more than one app through nord.