I managed 3600-18-22-22-22-52 at 1.35V, which has not given me WHEA errors yet. I might try tightening the subtimings a bit more later on, but I am happy to stop here really if it is stable.
According to
wmic memphysical get memoryerrorcorrection
MemoryErrorCorrection
6 ECC is enabled, plus I...