According to Wikipedia, DisplayPort 1.4 does HBR3 which can do 4K at 120 Hz. Why does GMK state "DisplayPort: 1xDP1.4 4K60Hz"? And worse, "Type-C: 1 (DP1.4 4K30@Hz ..."
Pity, I was hoping for an inexpensive but fast-enough mini PC that can be powered from a monitor and output 120 Hz 4K over the same USB cable. But apparently, this one actually can not do 4K over USB-C at all (I do not consider 30 Hz a usable frame rate).
The GMKtec NucBox G10 is now available globally. It's an affordable mini PC with the Ryzen 5 3500U and has support for up to 16 TB of storage and 64 GB of RAM. The starting launch price is $189.99.