TCKE 2 does indeed help - well found! This seems to be one of those hard to find borderline timings where you do several hundred percent in memtest then have a bunch of errors pop up within seconds. TRTP is another, I often find I can boot at TRTP 8, but at some point itll hard reset on me, then wont post until cmos is cleared. TRTP 12 fixed that (I see you already have it set chew*, just posting for anyone else who may read ).

You can try TRCDw 8 as well (assuming B-Die), though I dont think youll get that prime stable. My 3800x doesnt benefit much due to the single channel write speed, I suspect itll be harder to run but show more benefit on the 3900x (and 3950x).