I don’t know about that hardware specifically, maybe check the HCL. I have a Ryzen 4700U AMD machine and it works well with Qubes 4.1 (not tried it on any other version). IOMMU works on this machine, although my graphics, audio, usb and bluetooth are on the same bus, so I think aren’t isolated. But I’ve had no real problems. It’s a shame heads/coreboot aren’t a possibility either but it’s the price you pay for new hardware.
If you don’t mind less stability, I’d recommend installing one of Fepitre’s weekly build ISOs. Otherwise you may have problems installing. You’d at least need up-to-date linux-firmware and a recent kernel.
It would be unfortunate though if you plumped for it and couldn’t get Qubes going, so I guess that’s the crux of it. Do you want to roll the dice?
I don’t think UHD is an issue. You can scale XFCE in dom0 to 2x and set GDK and QT scaling. Or you could install KDE and have more flexibility.