This is one of the misunderstandings in the messy USB (or USB-ish) world. There is the physical connector (looked the same) USB Type-C "Connector". Then there are different interface specifications running on top of that physical connector. Examples are ThunderBolt 3, USB 3, etc. Note that ThunderBolt 3 (TB3) genrally is a superset of USB3 in some aspect, such as it supports PCIe and can run at 40 Gbps. USB 3.1 type 1 is 5 Gbps and type 2 is 10 Gbps. Now the eGPU's (externa GPU) interface is PCIe. There is no PCIe support in USB 3. That is the end of the story. You need TB3 for your eGPU attachment. LP Alpha/Delta does not have TB3.
