Since OPNsense was based on FreeBSD, EtherIP (RFC3378) should be supported native in the kernel.
Please add EtherIP bridging capability so that people can bridge mutiple seperate LANs accross the Internet.
This can be realized with Openvpn
Docs:
https://man.openbsd.org/etherip.4 (https://man.openbsd.org/etherip.4)