Ha. 90% of of your target user base for this monitor is Mac folks. and there are few Macbook Pros with USB-C. So please try to make an effort and test it with Apple Hardware too.
Anyway.. As per the spec you pasted up, it looks like USB3.0 would transfer data at USB 2.0 speed. And NO the upstream port doesn't help when connected to a USB-C laptop.
What a mess. I will probably return the monitor.