tCWL 16 on it's own is fine but 10 or 11 tRDWR under any circumstance does not POST at all.Set tCWL to 16 and you should be able to lower your tRDWR to 10. And, if you try to set tRDRD_dr to 6 I think it should be much easier to train.
From my own testing I also found that tCKE and tRTP cannot go under 8 or it will memory overclock failed POST.
I did manage to get tRDRD_dr to boot 6 so testing that now with TM5 Anta Extreme.
Do you guys think it's worth the extra voltage (and heat) to go for 4200-15-17-17-34-280-2T over 16-17-17-35? I need 1.60v vDIMM to do C15 while C16 only needs 1.49v ish. The DIMM's will get well over 53c on 1.60v if the GPU is also in use which is very close to the RAM. It isn't bad for the DIMM's but B-Die hates temp and might become unstable?