I cannot speak to the LTE B66 question - our experience has been limited to a few locations in California and Europe, and aside from the North America v. Europe divide, bands have not been an issue.
FWIW, Verizon recently upgraded their equipment in our part of the Sierra Nevada mountains, and where we used to be a B13 only region, we now additionally have B2, B4 and B5 with LTE-A support. That suggests to me that B2, B4, B5 and B13 are likely to be available on Verizon for the foreseeable future.
To get LTE-A support (well worth it in our region - speed improved literally 5-10 fold) we have been replacing BR1 US LTE models with BR1 Mini LTEA W models, and happily so. There is the added benefit that we can deploy these in Europe as well.
And they provide the integrated management structure of IC2 (and if you don’t use IC2, then you still benefit from the fact that the user interface and underlying technology presents similarly across all Peplink devices).
PS. The BR1s have been rock solid in our experience - the only reboots we have required are for FW upgrades and the like.