4K 60Hz requires an ACTUAL GPU not a usb dongle.

4K 60Hz also requires DUAL Display port 1.2 cables.

USB3 is NOT Thunderbolt 3 even though they use the same connector.

 

 

4K 60 Hz is supported by XPS graphic card, isn't it? And my XPS has Thunderbolt 3.

An EGPU with dual display port attached to thunderbolt 3 might work but the standard thunderbolt interface only has 1 and only 1 display port output not 2. 

You are demanding more bandwidth than HDMI or single Display port supports.

Never going to happen.