pimpx
mvidart2401
I think that several users have a beta bios that they obtained internally
How to get the beta bios?
I don't know of any beta BIOS for this. One user made their own BIOS version that somewhat helped with a couple features (a couple people were trying it), and you can find threads for that (I think on the z690 section). The functionality was
not 100% with those (or any).
As for what works, the 14900k and possibly 14600k (not the 14700k I believe) do boot in the latest BIOS versions, but not all features work properly (V/F curves are wrong for example). It isn't the latest micro-code, the frequency boost tables might be incorrect (but should work if entered manually like a per-core OC), ME version isn't right and won't work properly, etc. Basically, some systems will boot, but they won't be functioning properly. Kingpin did some testing and a few others and they can overclock and run benchmarks, but it may not be fully stable for a 24/7 system and it requires manual tuning of everything.