Thanks, that's really funny! "On the other hand" is my general approach to life, so I'm happy to argue with myself.

And yes, I'm steelmanning. I think this approach is an excellent one in some cases; it will break down in others. I'll present a first one in the next article. It's another box you can put coins in that (I'll claim) can't usefully be modeled in this way.

Here's the quote from Jaynes, by the way:

What are we doing here? It seems almost as if we are talking about the ‘probability of a probability’. Pending a better understanding of what that means, let us adopt a cautious notation that will avoid giving possibly wrong impressions. We are not claiming that P(Ap|E) is a ‘real probability’ in the sense that we have been using that term; it is only a number which is to obey the mathematical rules of probability theory.