Forgive me if I am misunderstanding something, but...
If you look at the example screenshot below:
It shows tha LAN_POS interface as an option for failover / load balancing. This would be invalid, as it is not a WAN / uplink but merely a private VLAN. If the RutOS were to make this the default route, it would be problematic for sure.
Why is this interface even appearing here?