Similar results here. Decided to stick with 3200 instead of 3600 due to the large increase in IO and SA needed to boot my system vs 3200. At 3200 I have IO at .98 and SA at 1.0 in bios. Might try going lower.
Might be selling my 3D Printed rear fan holders soon. Don't believe I'll be able to use them once I install my top and side panels. Shame since I noticed a big difference in ram temps when facing the fans to blow air at them.
Think I'll be sticking to 3200 for now on even though I am able to run 3600 with my sticks. I can drop IO and SA all the way down to 0.98 and 1.0 respectively, meanwhile for 3600 I have to have them in the 1.20+ ballpark. Is IO and SA a ram module related thing or is it more tied to the specific CPU utilized?
Whether I was using iGPU or GPU the first Asus Logo screen would show up. The problem was when trying to enter bios my PC would just freeze with a black screen. I seemed to have fixed the issue by removing my m2 drive and clearing the bios and plugging it back in. Not sure if 0906 is to blame but between this issue and the 800 mhz bug if IO and SA are left on auto this bios version has been a real PIA on the Z270G.