In my experience, once you have the scores, schools will be eager to host your child for a visit. 226 is clearly awesome, and unless your kid has Cs on the transcript (unlikely) or some really bad criminal/behavioral problems that would lead to his school guidance counselor not writing a good recommendation, it’s pretty much guaranteed they’ll be a NMF.
So, I’d just send a brief email to the admissions department at the schools your kid is interested in. “My son, Joe, graduates in 2021 and is highly likely to be a national merit finalist, given his PSAT score of SI 226, great grades, excellent character, etc. Joe is really interested in University of Big NM Money, especially your XYZ Program " and we’d love to visit this spring. We liven CA, so we’ll need to well plan ahead to allow travel time, etc. Can you connect me to someone to help me arrange the visit for March?”
IME, some schools (like U Alabama) will be all over you like white on rice, and will make it very easy and create a delightful experience. Alabama did all the recruiting through the honors college, but arranged visits with professors in the departments my kid was interested in as well as the main campus tour, etc, in addition to the honors college visit. They produced an “itinerary” for her day and a half long visit, with meetings/tours/etc throughout the two days. It was easy as pie.
Others won’t be as good at recruiting, and you may need to do more leg work to arrange visits to each aspect of the university you want to see, but all their admissions departments are designed to RECRUIT your kid. They WANT your kid. This is what they do. Just reach out, and take it from there.
So, I’d go ahead and send emails as soon as you have a general idea of when you want to visit. (Or earlier, if you have questions.)
(I’ll be doing just that – sending the emails – to Washington State, U Idaho, and U Ky in the coming weeks, once my kid and I have nailed down the dates we’d like to visit . . .)