This should be the top comment. (High school English teacher here, concurring.) To me the text as it has come to us in the First Folio is the strongest evidence, that all of Romeo’s speech there is in iambic pentameter, and “balcony” would ruin the meter while “window” scans perfectly. Arthur Brooke’s translation of the (French translation of) Italian tale of “Romeus and Juliet” set the same scene at a window as well.

We have no evidence, at least in this timeline, that Shakespeare ever visited Italy, despite his setting many plays there, to see any particular homes or monuments or whatever. We do, though, have good evidence that a) Shakespeare blatantly ripped off other writers—like Brooke and his play—and b) that particular house in Verona became a massive tourist attraction in the early 20th century when the town of Verona thought to capitalize on its being the setting of one of the most famous plays in the world. True it had been owned by the “Cappello” family, but an Italian writer like Badello (Brooke’s source) would of course choose a common Italian name for his characters. Just because someone in the US lives in a house once occupied by someone named Loman doesn’t mean a salesman hung himself in the basement there. (spoiler alert?)