Credibility moves, like status moves, cannot be self-recognising and still effective. I believe this, you don't, there's our disagreement.

I'm not sure I agree with this either. You can't make a self-recognising move to gain credibility that is effective? Since it should be impossible to (predictably) make a sequence of difficult claims to a greater degree of impressive reliability than previous credibility judgements would allow. This demonstrates that you have at least the capability to give trustworthy utterances. This gives you more credibility when there is a reason to expect you to be attempting to make good claims.