Mainboard is more or less the same. For maximum core compatibility, only one USB host port is routed to the core.
The USB host port is then multiplexed into 4 downstream device ports with a GL850G usb hub chip.
These four ports are then routed to:
- The cpi keyboard (pogo pins connected)
- A type-A port along the mainboard edge
- and 4 to the mPCIE connector
- the 4G dongle most probably takes one of that
The question is whether they leave pads/pins for the last usb port on the 4G expansion board.
If so we can expand it like this: Internal USB hub mod