My son (high school class of 2021) applied to Bates ED2, having never visited the campus, and got in. This is not generally what I’d recommend - for my own children or others - but it was summer of 2020, right in the middle of Covid, and campuses were not welcoming visits, especially the Maine schools. He had done a few official tours prior to Covid, and lots of unofficial visits, walking around campuses, etc. but the Maine schools were particularly adamant about not wanting outsiders on campus. He applied to another LAC ED1 and didn’t get in, and then become really confident that Bates was his clear second choice - it ticked all of his boxes. So, he applied, got in, took gap year right after he graduated, and had his freshman year there last year. He loves it! I was nervous, but it turned out to be a great decision and he’d very excited to go back for his sophomore year.
OP, in your son’s case, he has seen the campus, and even had a tour, plus he’s seen lots of other campuses, also with official visits and tours. I think your son is in a great position to be confident about his decision about Bates. If he applies ED, Bates is certainly not going to question his commitment, so if he’s sure, I think he should go for it!