It seems that the contradiction is deeply embedded in your thinking. You can't have it both ways.
Either the supernatural *is* testable and it is unfairly ruled out or it *isn't* testable and it has to be an a priori assumption that can never be validated. Pick one. But if you pick the first then be prepared to argue for it.
Take your example of the "divine proportion" - can you offer any genuinely testable explanation ? How can you ACTALLY verify that it is the product of the divine ? Or is it that the reason why one has to be biased in favour of the conclusion to accept the argument simply a sign that the argument is so weak as to be of no value ?
And I'd also appreciate it if you didn't try to evade discussion of the contradiction in your arguments by misepresenting - or in this case - fabricating - my position.
Methodological naturalism does not exclude intelligent design. "Intelligent Design" says so as an excuse to explain away their failures.