I disagree that it’s simpler, because most VPNs will use dynamic IPs. So any time your internet flickers or your power goes out, you’ll need to reconfigure Transmission with the new IP. Sure your method works for a kill switch. But it requires manual intervention every time it gets killed. With qBit’s interface binding, it doesn’t care what the VPN’s IP is. All it cares about is that it’s using the specific interface. So if the VPN is disconnected (and the VPN’s interface has no connection) then qBit simply thinks there’s no connection to the internet.