When discussing these third-person as you are now, cognitive algorithms as algorithms are being invoked. But we all know that "p" and "Alice thinks that p" are hardly reducible to each other, it's first-person items like "I believe that p" that are deflationary. So while it is clearly the case that you can imagine situations where the sky is not blue but it would be epistemically rational to believe that it is, that does not demonstrate situations where one could justifiably claim only one of "the sky is blue" and "it is rational to believe that the sky is blue" (indeed the justifiability of the former just is the content of the latter.)