Give it the ol' "Chuck it in the Oven and Re-Flow" I say. Though I'm sure it's not that heh

Oddly, I've gotten code d2 a couple times when attempting 3466, which to me doesn't make sense (to me *shrug) as it pertains to "PCH Initialization Error"
Usually it's F9 for a second and a half before its power-off-wait3sec-power-on cycle. Thinking I need to download the updated manual, because F9 is "Recovery capsule is not found" (Unless this Recovery Capsule is supposed to be an AMI Module that attempts to correct whatever's problematic to establish stability?)

I tried your suggestion of higher ODT, even tried using all the timings in that ONE time 3466 worked, then tried relaxing all the Sub-Timings by one tick. Then gave 20-20-20-42 a shot, still no dice lol

Not sure if you're willing to comment (as per your previous statement regarding competition and this being a popular thread), or if you perhaps have a good resource to refer me to (like a guide someone has written), but this is such new territory for me that I basically have tons of questions haha Granted, I'm not against trial-and-error, to learn myself, but with how slow systems take to POST now... that method takes roughly 8 to 10 times longer than in the past
-Not sure if I should be trying a higher "Training" voltage or not? Currently it's automatic amount for (I think) speeds >3200, is 1.5V. No clue is 1.55V would make a difference, or if your past advice of "sometime less voltage" would apply to this...
-Or maybe manually set the DRAM VREF to 1/2 of the DRAM Voltage? I've been reluctant to touch that option because on the Titanium, and Ryzen Master, they both trigger there warning colors after only like 20mV (so .600V being default, .620V being red, and I'd need to set .680V for 1.36V, or .700V for 1.4V )
-For all I know, I need to raise tRC (though yours was an XMP profile level of low at 50, in the one SuperPi shot, but your main timings were also very tight), or maybe the tREF. There's a tRCPAGE option as well, with a range of 0~1028T, but it always reads 0 and nothing else seems to be able to report a value for it; thus, wouldn't even know where to start! heh
-Someone else has suggested to me (on [H]|Forums) "Since you are using single row modules, try disabling BankGroupSwap", which is a present option on the Titanium, at least in my modded 1.72 Beta.

I put a request out in the Memory Speed thread on there for BIOS shots from two guys, both I think who have CH6's, but one is running at 3466 and the other at 3600. Am hoping that, maybe, just through comparison I'll be able to glean a bit of info that'll point me in the right direction.
Thankfully, I find this enjoyable (at least when the BIOS is behaving), so will just have to keep my fingers crossed!