We took S18 to 3 schools within driving distance - small, medium, large - on a long weekend junior yr. He decided on small. We then took him to accepted days at a couple he was more interested in once he got in and another that he missed a day of school for when accepted. So, he didn’t see many schools, picked one, and loves it there. My guess is he may have felt the same about a few of them - he’s incredibly easy going and social. He also had no particular major he needed.
I think because each kid is so different, it’s hard to put a number on how many to see and when to do it. I also think it’s very important to see the LAC in session because you get a much better sense of the type of kids there, whereas at a larger school, they’re bound to find “their people.”