This is very cool ! One thing that worries me is that if we discard the votes, it means we lose the info of who casted votes and let a block become irreversible, we retrospectively know who were the 21 who were allowed to vote on it but not who were the actual 3/4 who did, Although I guess at this point, if 3/4 managed to vote a "bad" block in, governance has shifted anyways. But it may be important for legal action should it be a double spend.