How about you assume less? I spent 40+ minutes looking for this here, here, here and here and I’m already fairly familiar having done work on two other ActivityPub based projects.
In addition public-addressing (or the lack of use thereof) in no way claims to achieve what you’ve stated - which is probably why it’s not the answer to my query.
When managed in A/B install partitions by a third party org that layers their own stable/alpha/main versioning over the top? ;P