Did you ever manage to get vGPU's working in any other hardware configuration? I know it's not what Hx00 customers want. I bloodied my forehead on that for a month or two with Cloud Hypervisor --- I got to the "light reverse engineering of drivers" stage before walking away.
We didn't focus on vGPU and largely avoided it on purpose. Instead, we focused on whole-GPU and NVSwitch-partitioned passthrough (Shared NVSwitch Multitenancy Mode), which is a better fit for the workloads we care about.