6600 xt and Big Sur initial install

[dasboot5]

I want to be clear on my understanding of the 6600xt Navi 23 card and installing Big Sur from scratch. The support for this card comes initially from 12.1 Monterey, and there is no support for it in Big Sur, so installation with B.S. will fail. So the workaround is to use a supported card to install Big Sur (removing agdpmod=pikera boot arg as required) and then add back the boot arg for the 6600 XT and the card in place of the temp install card and then upgrade to Monterey or Ventura.
Or, install Monterey or higher clean if you can accomplish this...
Is this the correct install procedure?
I am building a new machine with an Asus Rog Maximus XI board and a 9900K and a 6600 XT and my test flash installer was failing with the card just spinning its fans up to max, then I went back to the OC guide to check support and none for this card in Big Sur was the result. All my machines are on Monterey but they all have been initial installs of Big Sur then upgraded and this is my first Navi 23 install. Not had good luck with clean Monterey attempts.

 

[Middleman]

Yes that's the correct procedure. Unfortunately the only supported cards you'll find for Big Sur are the 6800 & 6900XT.
In addition to agdpmod=pikera you need to also define your Intel IGPU with AAPL,ig-platform-id as well as device-id, and also add the RX6600's properties into the PCI device tree. As your CPU is 9900K your Intel IGPU should be found on your chip's Intel ARK specs page (which is 3E98). You use that as device-id also like this:

For the RX6600 we use the following settings: