The point is in showing that having a magical kind of knowledge certified by proofs doesn't help (presumably) in that thought experiment, and hopefully reducing events of possible worlds to logical statements. So I want to use as many logical kinds of building blocks as possible, in order to see the rest in their terms.

Fair enough. To me it seems more illuminating to see logical facts (like the parity of Q) as physical facts (in this case, a statement about what certain kinds of physical mechanisms would do under certain circumstances.) But, at any rate, we seem to agree that these two kinds of facts ought to be thought of in the same way.