In the UBR LTE datasheet it is mentioned that the device supports SpeedFusion, but it does to really say if also the bandwidth bonding is supported with no additional cost across all LTE and WAN ports. Thank you.
Yes it does, I have had it bonding 2 x LTE and 1 x WAN.
It is worth pointing out though that the throughput across the speed fusion is not that high though
As long as your device has valid PrimeCare coverage then you can use Bandwidth Bonding.
See here: UBR LTE datasheet