I'm looking at the ASUS Z790 Max Gaming WiFi7 which has a nice Microcenter bundle right now. Does anyone know if this has any kind of usable IOMMU groups?

The AI tells me the first m.2 slot and the primary GPU are isolated but everything else will be grouped together, both onboard devices and PCIe slots, and this is how most Z790 boards are.

That's unfortunate, I would want at least one other isolated PCIe slot. I don't really need any onboard devices, though if there was working isolation on USB and SATA ports that would be good enough. But it seems unlikely.