I wasn’t able to get the KVM router image to boot in Proxmox 7.2. I’m able to import the image and attach it to my VM with UEFI BIOS, but it’s not recognized for some reason. I also tried non-EFI SeaBIOS. The symptom in both cases is “no bootable device.”
I ran into a similar issue in the past with the Hyper-V image, but I was able to convert that one.