I had some similar thoughts to yours before reading that, but it helped me make a large update in favor of superintelligence being able to make magical-seeming feats of deduction. If a large number of smart humans working together for a long time can figure something out (without performing experiments or getting frequent updates of relevant sensory information), then a true superintelligence will also be able to.
Have you read https://www.lesswrong.com/posts/5wMcKNAwB6X4mp9og/that-alien-message yet?
I had some similar thoughts to yours before reading that, but it helped me make a large update in favor of superintelligence being able to make magical-seeming feats of deduction. If a large number of smart humans working together for a long time can figure something out (without performing experiments or getting frequent updates of relevant sensory information), then a true superintelligence will also be able to.