Beta 7 doesn't like to install on SMBIOS with T2 apparently.
But you can work around that:
Copy your EFI to a USB and set SecureBootModel to "Disabled" and SystemProductName to "iMac17,1"
Leave your main EFI on j160, use the EFI from the USB stick for the first reboot.
But be aware, Beta 7...
If you go above 3600 MHz your FLCK is going to 1:2 and you lose performance instead of gaining. It's always good practice to run a benchmark after each change to see if you improved or are going in the wrong direction.
The X570S is just an X570. It the same model number according some reports, so same silicon. The only difference is board around it.
Probably just a concession from AMD to board partner since they didn't release an X670 with Zen 3 to sell new boards.
Don't get me wrong, that board is a beautiful piece of engineering.
I could just not justify that price tag for myself because I don't see enough value in return. But it would surely be interesting to tinker around with it and see what you can get running on MacOS :)
In the good old days you...
The main problem is, that this board just makes no sense at that price. For 200$ or so more than a C8E + 5950X you can get a PRO WS WRX80E + a 3955WX. That’s octa channel memory and 7 full 16x PCIe slots. And the board also has 10Gbe.
You can get a board for less than half of that, add a 10Gbe...
I can't really say anything about the AQC113CS, though I'm using a USB-to-Ethernet dongle with the AQC111U. That one worked out of the box with MacOS, but was limited to 1000Base-T, only after installing the driver kext from Marvell it would run at 5000Base-T. But that driver is specific for...
I don't have an I-225V, but I'd assume it should be working on Monterey too since the i225LM is supported natively by macOS. The I211AT didn't run because the SmallTree Kext does not work with Monterey.
If you're worried about compatibility just install Monterey alongside Big Sur on a new APFS...
It is sluggish because there are no drivers in macOS for it, and macOS relies heavily on hardware acceleration to render the UI.
At this point is is not very likely that the lower Navi 22 and 23 cards (namely the 6600/6700) will get any support, otherwise Apple would already have implemented it.