What's the status of the Proof-of-Authority module?

The first sentence is the Cosmos SDK documentation says:

“The Cosmos SDK is an open-source framework for building multi-asset public Proof-of-Stake (PoS) blockchains, like the Cosmos Hub, as well as permissioned Proof-of-Authority (PoA) blockchains”

Unfortunately this is not true, as there is no official PoA module for the SDK.

So what’s the status on it? I was able to find in-progress development but that were all stagnated 3 to 4 years ago, yet I can’t find the reason why they didn’t move forward.

@marbar , @Tectract , I see that you were active in this subject, maybe you can clarify the situation?

@romef , @svylabs , you were also looking for a PoA module in the past. Were you able to find one?

AFAIK PoA / PoS difference is simply white listing validators