Mikrotik has these three current models which host an LTE modem in an outdoor case with gain antennas. All have an AR9331 SoC with 16MB of NOR flash and 64 MB RAM. The wifi radio feature of the AR9331 is not connected to any antenna, so there is no wifi. The modem fits in a PCIe slot with USB2 interface. They offer three different modems, though none of them are really all-purpose all-bands.
LHG-LTE-R Dish antenna, single Ethernet and single SIM
LDF-LTE-R Feed unit for customer supplied dish, probably internally identical to LHG-LTE.
I don't see anything about these in the firmware selector or wiki. I own a SXT and LHG, and though the stock firmware is fine for a basic modem bridge, support for third party modems is lacking.
The Leds may not be correct and you need to add all the modem support but it does work.
They are supported in ROOter for a large number of modems. I have a SXTR-LTE-R and it works fine with other modems than the R11e that comes with it. That is an Ethernet modem with almost no documentation about it.
The LHG-HB build does boot up, but the USB bus does not work-- it is not enabled in the DTS. So I used the wAPR-2nD build instead-- but also no USB. This is a bug since the wAPR-2nD is designed for USB peripherals. Modifying the DTS does seem to have USB working, but as noted the LEDs are all wrong I'll try to sort that out next.
Trying to decide if this should be a new model or an extension of the LHG-HB. The LEDs are almost right for the LHG-HB but they are wired active high instead of active low so they are out when they should be on.