it's precisely the formal logic, albeit mostly in legal, that employs double negation to cover all bases, in case of doubt about the excluded middle, and import

it's precisely the formal logic, albeit mostly in legal, that employs double negation to cover all bases, in case of doubt about the excluded middle, and importantly, to reverse liability of proof. You are not not an idiot. I didn't say you were one, but I will leave the proof to the opposite to somebody else. It might just be an intensifier, irregardless of the legalese, whenever it defaults to the law of excluded middle, that is, perhaps when the proof is not even considered relevant, whereas "regardless" implicitly connotes neglect. Regardless ofyou being an idiot. or Irregardless of you being perhaps an idiot. Alas, double negation tends to be not very stable in informal speach, e.g. any "some", not any "none", not not any: "some", "any" or "all". This involves type coercion from the gradual to the binary interpretation (and it's terribly difficult to make explicit, exactly not trivially simple at least).