Hello everyone. I think a good idea would be to introduce an EOIP tunnel like Mikrotik used. This is a very interesting option for building tunnels when you need to bridge 2 remote network segments into a one broadcast network domain with MTU 1500. On Github there is an open project GitHub - bbonev/eoip: Linux kernel mode EOIP tunnel (compatible with MikroTik), which is supported by the developer, but he doesn’t know Vyos, but he’s going to contact. His project requires compiling a kernel module.
It is possible that due to patents it is impossible to name the tunnel as EOIP, but nevertheless, as I understood Ethernet encapsulation in GRE, this is a very useful feature to avoid problems with pure GRE or L2TPv3 when bridging with Ethernet and packet fragmentation.
Also, the presence of this protocol will allow you to use Vyos as a high-performance root router, and Mikrotik as a router in a remote side.