BR1 Mini connecting to a Balance router question

Can a BR1 Mini be connected to the USB WAN port on a Balance router?
Physically, there are are Ethernet ↔ USB adapter cables, so the LAN port of the BR1 can be plugged into the USB port on the Balance. But software wise …

What are you trying to do?

Some Balance models allow the use of the USB port as an ethernet WAN port when equipped with an ethernet-USB dongle. See ethernet adapters on the USB port thread in the forum.
I assume the context is to feed the LAN of the mini into the Balance as an additional WAN source?

Yes, that is exactly the idea. A Balance 20, for example, supports 3 WAN connections, but only two can be live at any one time. I was hoping to use a BR1 into the USB port as a third WAN connection for failover.

Thank you for the link. That was exactly my issue.

The USB<->ethernet setup seems to work well on the models that support it (in my limited experience). W.r.t. the overall architecture, at one location we are using a BR1 in a similar way - an HD2 with two cellular connections and the BR1 providing a third by connecting the BR1 LAN to the HD2 WAN port. Works like a champ.

Thank you.