Hey sorry for the late reply... war 'n stuff happened

))...
On catalina there is no problem on any system but the Problem starts with FireWire card/audio devices on AMD System:
Card gets recognized soundcard gets recognize but the device malfunctions (no sound, inputs work but no output signal (I have the same Focusrite Saffire card that you guys showcased)
On Intel System:
It was exactly as the AMD system but per your guide enabling VT-d fixed everything
On VM's (QEMU -machine q35):
The card is seen by macos but there is a problem that it cannot list any devices and nothing works.
QEMU -machine pc:
is the same as the AMD system
Thing that i have tested:
-Different Firewire Cards (one via chipset one texas chip supposedly OOBE on macos)
-Different Sound cards (Focusrite Liquid 56, Focusrite Saffire 24, Mackie Onyx Blackbird... all dice chips)
-As mentioned above different platforms (Intel, AMD, VMs)
-Different machine type and cpu models on QEMU (Penryn, Haswell, Cascadelake, Host-passthrough)
P.S. I know that Firewire support was dropped on Monetary, needless to say these cards all have third party drivers which makes them work and as mentioned above i know they work because there is no issue on the Intel Hackintosh with VT-d enabled and one more thing my issue is present (on problematic systems) even in BigSur.