Issues with anything older than Win10

So I have run into an issue that is less than well documented online. This issue is related to gpu passthrough. For sake of elimination I am running a gen 2 ryzen(zen+) system, with two GPU’s installed.
A single RX580 for the linux host and a single RX 590 for the window guest. I have run this configuration successfully using QEMU with the virt manager front end flawlessly. On the latest version of windows 10 without fail except for some random bugs that sometimes crash the host.
They are rare and even more so when I upgraded the ram on the system. The moment I however try running windows 7 and install the drivers for my RX590. They fail to function and I always seem to get an error. Either code 10 and or sometimes code 12 this persists in either EFI or BIOS mode in the VM. There also seems to be problems with using usb hubs which may perhaps be unrelated or not.
So I am really left with some questions about how to address this problem.

Windows 7 doesn’t support EFI (well enough to count).
AMD has a habit of requiring a working EFI implementation for their RX series of graphics cards to work correctly.

I’ve already attempted to use a version of windows 7 that supports efi. That from what I understand functions provided it is running natively.