The VT4900 KVM docking station utilizes two different chipsets to operate. The two DisplayPort outputs will utilize DisplayLink drivers and can operate on any version of USB-C. However, the HDMI port will require a USB-C port featuring DP Alt Mode or MST support.
As you will have 2 separate systems connected, you need to make sure that they both support this feature or you will not be able to get that third monitor to appear in all of the different configurations.