Will the Radeon VII support Crossfire? I would really like it to. NVidia is now doing VRam Stacking with their NVLink, so if these are doing crossfire, can they vram stack?
Also, is the RX30 series (or an RX 6 series or whatever) still going to be a thing?
Now you can use mGPU in DX12. About DX11, the driver already has the AMD Crossfire option, but the game is not yet supported. I believe that the follow-up version will soon improve it.