List of Intel Titan Ridge Thunderbolt 3 Devices
The plain USB-C mode is transmitting USB and DisplayPort signals. There is no PCIe support. The only way to get PCIe from USB is using the JMS583 chip from Jmicron which does UASP to NVMe conversion (but will not work with any other type of PCIe device, even PCIe AHCI SSDs).
Pending: Add my system information and expected eGPU configuration to my signature to give context to my posts