I have passed through a second nvme which got assigned to PCI 05:00.0 and after setting the romfile to AMDGopDriver_8745hs.rom (and NOT AMDGopDriver_8845hs.rom!) I got for the first time a HDMI DisplayLink output on my monitor with this setup:
agent: 1
args: -cpu 'host,+hv-emsr-bitmap,+hv-frequencies,+hv-reenlightenment,+hv-tlbflush-direct,hv_ipi,hv_relaxed,hv_reset,hv_runtime,hv_spinlocks=0x1fff,hv_stimer,hv_synic,hv_time,hv_vapic,hv_vendor_id=intel,hv_vpindex,-hypervisor,+invtsc,kvm=off,+kvm_pv_eoi,+kvm_pv_unhalt,host-phys-bits=true'
bios: ovmf
boot: order=ide2
cores: 2
hostpci0: 0000:66:00.0,pcie=1,romfile=vbios_7xxx.bin,x-vga=1
hostpci1: 0000:66:00.1,pcie=1,romfile=AMDGopDriver_8745hs.rom
hostpci2: 0000:05:00.0,pcie=1,rombar=0
ide2: none,media=cdrom
localtime: 0
machine: q35
memory: 8192
meta: creation-qemu=11.0.0,ctime=1781373753
name: BazziteVM
net0: virtio=BC:24:11:92:EE:F4,bridge=vmbr0
numa: 0
ostype: l26
scsihw: virtio-scsi-single
smbios1: uuid=524cd184-c115-463a-8085-dacbaee096b6
sockets: 1
vga: none
vmgenid: 0f7ec33c-c241-433d-b4c9-1f966dbe0096
Now I'm going to check some distributions (not using Windoof).