Can someone give me some advice on hotspots and US Mobile for use in a truck?

I recently got a new F150 that has an integrated LTE hotspot with ATT. I live in New England where if you move 5ft in either direction a different carrier has better or worse signal so ATT isn’t ideal everywhere. I also drive a number of other places out in the sticks where one carrier may work better regionally over others. I stumbled upon US Mobile and the idea of carrier roaming is appealing. Im wondering if it would be possible to use US Mobile with something light a Netgear Nighthawk M5 or one of the 5G wifi routers from Cudy that appear on Amazon. If this works I’d probably get a Sierra Wireless router or something more industrial. I’d primarily be using this for wifi calling and reliable signal.