Somewhat “missing the [legitimate] point” you are making, the island in question is literally “Μελίτη,” transliterated “Melité” which could be this:
I don’t know if it “works” in terms of the trajectory of Paul’s journey, but I have a hard time believing that “nobody in Acts knew about Malta,” which is prominent enough in the Mediterranean and was under Roman control by 218 BCE…and Mljet has venomous snakes…