Wanting to check before purchasing Asus RT-AC85P

I'm in a location where I only have 4G internet through a sim card. I recently found out though I should be able to use a OpenWRT router with a USB connector that takes my 4g sim card.

I've been looking at the ASUS RT-AC85P. As far as I understand the wiki the wireless is compatible and should work. There's no strange version where this wouldn't be the case?

And on top of that any 4g usb adapter should be ok?

you'll need more than just usb and a sim card reader.

haven't seen any posts regarding rebranded versions of this specific device ...

yes, but it never hurts to search the forum, before buying.
another option could be to use an old cell phone as 4g modem.