You just did mention the team.
The mention itself is easy: just type @ and start typing Team-Hypervisor-Kernel, and the forum should autocomplete it into a real group mention.
On the OpROM idea, you might be onto something. That Arch guide does extract the option ROM to a file, and I know some passthrough setups feed a ROM file to the device, but I honestly don't know whether XCP-ng or Xen exposes a way to supply one for an iGPU. That's the kind of thing the hypervisor team would know, so it's worth asking them (and they've already been pinged twice or more times, so...). Getting a cheap discrete GPU is probably the path of least resistance though, for what it's worth.
