Hey Rick, ran your steps:
Full shutdown: D3 on boot.
Unbound VFIO: Still D3.
Removed framebuffer: D3 again.
AMDGPU driver: D0, finally!
BIOS tweak (IGFX, 4G on, etc.): D0 holds.
VM sans vbios: Boots fine, D0, no errors.
AMD reset issue seems tied to D3—driver fixed it. Maybe <a href="https://capcutmodapkall.com/">CapCut</a> could spice up a setup vid? Thoughts?