Hi ,
Welcome to our new Microsoft Q&A Platform.
I want to say that your current discovery is correct, Microsoft on how to do this is just using DDA. which works from Hyper-V Server 2016+.
Let me explain something, smart as you maybe have known all of them:
1.GPU acceleration is based on RemoteFX, which is part of the Remote Desktop Service.
2.We need to be aware of is the fact that not every Hyper-V virtual machine can take advantage of GPU acceleration. Obviously, guest operating system support is required, but there is more to it than that. When you create a virtual machine in Hyper-V, you are asked whether you would like to create a Generation 1 virtual machine or a Generation 2 virtual machine. Generation 2 virtual machines do not include an option to add a RemoteFX 3D Video Adapter. The option exists only for Generation 1 virtual machines.
3.The config UI of RemoteFX vGPU has been removed from Hyper-V Manager of Windows Server 2019, you can configure RemoteFX vGPU by using Powershell on Windows Server 2019.
Best Regards,
Candy