FWIW, we don't play with the errata, because the pre-errata rules are right there are on the cards, and what am I going to remember, the rules on some website, or the rules right in front of me? The main issue is that if we ever have some rules question about, say, Band of Misfits, well the online faq pertain to a set of rules we're not using, so it's up in the air what we do about that.
And I guess in principle we still have the issue of, I Crown an opponent's Estate with the abilities and types of Caravan Guard, and use Way of the Mouse to play a Lurker to gain a Mandarin, and so on. We'll live, somehow.