Cant use bridge mode with usb tether?

So I have the A1300, im trying to use this as a failover wan for my main pfsense router that runs on fiber. My main source is an iphone or android that someone will hookup when it goes down so it won't always be plugged in. If i go tether, i tried putting it in ap mode bridge but it says it has to have a ethernet wan connection, if i do wireless repeater bridge and i disconnect my phone i cant get it to automatically reconnect to my hotspot and also cant access my glinet admin interface without manually setting up an ip / etc...Anyone got any ideas for this?

If i just use router mode im double nated and i cant have that because of the complex configs with pfsense for the company.

Failover and bridging, also called inline failover, is very complicated.

I don't think A1300 works with bridge and tethering. Maybe it works but I didn't try. Even you get bridge working you may not get the failover working correctly.

Best way is to get the pfsense working under double NAT.
Setting the A1300 DMZ to the pfsense could also be an option?

Yea i looked into dmz but wont work either, currently I am testing repeater mode joining iphone hotspot, then sharing that connection on lan1 to pfsense lan that takes dhcp and it seems to be working. Still testing if it will auto connect if i turn my hot spot on / off to get it more automated, but so far it seems to be working. Its unfortunate glinet cant do bridge mode with a usb tether as main connection and requires wan from ethernet. Unless there is some plugins or settings i dont know about...

To be honest I don't know if bridge mode works with tethering. At least for modem bridge is not working.

But there is one term called IP passthrough.