Your son wants to apply to over 20 schools? He really needs to pare down that list, and the visit process can be part of that by helping him not only cross some schools off, but also focus on what he’s really looking for. At this point saying “20 Ivy and LAC, which are scattered all over the country” sounds like a prestige list and not a thoughtfully compiled one.
There have been lots of threads here on CC about applying to that many schools. Here’s one: http://talk.collegeconfidential.com/parents-forum/1707730-how-many-college-applications-are-enough-p1.html. The quality of the application suffers when you do that many, particularly the “why College X” supplements.Also, the wave of rejections can be brutal. My D had a classmate a few years ago who applied to 23 schools. His list was super reach heavy. He got into 2 of 23, and they were match schools. I remember his mom telling me how brutal it was to get that wave of rejections over the course of several weeks.