Mesh11sd & 802.11s Issue

You are probably right - here is the use case for extra context: 3 vehicles not always in range of each other. Each node providing local network within the vehicle at all times then when vehicles are within mesh range to allow routing between the client devices behind each mesh node. The reason for the single /16 and different DHCP scopes is I need multicast traffic to work and wasn't sure it would work cross subnet.

See this post - Rocket M5 XW Firmware - It seems only the XM is supported which is odd as it's an older hardware revision.

That's by design - this is for off-grid network where internet access can't be guaranteed so making sure all the mesh side is working first before dealing with internet access.