In any case, I think that if I personally block a domain this should have the same result for me as admin based instance blocking. Either this is already the case (and this is my understanding of @Gargron), or not, and then it should be fixed.
All this #fedipact and #defederation seems more an emotional and idiological discussion to me. Absolutely fine, and I see where people are coming from. As long as it's based on technical facts, not misinformation.