Created an account just to say thank you, my god thank you so much. I've been banging my head against this same problem for a day and a half and finally I stumble upon the exact solution.
I don't understand why OpnSense doesn't let you set a gateway on a Wireguard interface, but this is a perfectly adequate workaround.
I don't understand why OpnSense doesn't let you set a gateway on a Wireguard interface, but this is a perfectly adequate workaround.