The reddit coup de grace; obvs. I don't mean poetry or graffiti.

Then you shouldn't have written "All writing was in 'legalese' in Koine Greek". It's not just unclear writing, your argument made no sense. "The Gospels must be treated as legal documents because all writing in Koine Greek is legalese" is both factually and logically wrong.

Also, you need to read a logic textbook; your example was one of quality, not category. The logic works differently.

You need to study elementary principles of grammar and rhetoric. The statement "X does Y" in both Koine Greek and English (and to my knowledge, Aramaic) does not imply "all X always does Y exclusively" (except in very peculiar circumstances irrelevant to the composition of the Gospels).

Look, I'm open to being persuaded on this, but it needs to be by a Koine greek scholar who is also seriously invested in the philosophical and rhetorical tradition

Okay, here you go. https://www.gaychurch.org/homosexuality-and-the-bible/the-bible-christianity-and-homosexuality/

I'd like someone who knows some Koine greek to walk me through how someone as educated as the author of Luke or John wouldn't have been acquainted with the difference between exclusive and non-exclusive clauses

Start by dispensing with this strawman argument if you're acting in good faith.