I think that you are probably the first guy in years which actually did a full writeup about using ECC RAM in AMD consumer platforms, and even more important, you actually tested how it behaves during failure to prove that ECC is working. That info is REALLY hard to come by, is almost impossible to get any sort of conclusive evidence.
However, when you say that it is an "incomplete implementation"... how does a complete implementation works? What features are missing (ChipKill? Recall it from screenshots of some Dual Processor Motherboards Firmwares)? Are the failure behaviors of other platforms as well documented as you did with your AM4 system so we can compare?
Some months ago I did
this Thread here about ECC in Intel consumer platforms, since it has been proven that you can plug RDIMM ECC with a Xeon E5 in a X99 Motherboard and that it at least boots (No idea what happens with a HEDT Ci7 and RDIMM ECC). However, I couldn't find any convincing info regarding if ECC itself works or not. And Software misdetecting it makes the situation worse than it is, because the only way to tell is to force errors onto it.
