My 2 cents is ask for the pre-read at HA schools now, whether HA D1 or D3. They should be able to tell you fairly quickly whether your son fits the academic profile for an athlete. We learned the lingo a bit late and once we asked for the pre-read from schools we had even sent the grades and scores to, we fell short at a few that we thought were real contenders. So, instead of wasting time communicating with coaches only to find out you not in the right "band", get it out of the way. If your son throws 98 and is a lefty, it might not matter lol. Some Ivies are fine with 1200 SAT and then some HA D3s won't even look at you with less than 1450.
Then, armed with that knowledge, do a side by side comparison of Showball and Headfirst, and I mean session by session to see which one has the most target schools attending. We had great success with both and did them multiple times. Once spring season starts, have your son reach out to coaches and get on their radar and share videos and stats. That way, when you pick a session and find out if they are looking for a player in the position and grad year of your son, you are ready to roll.
The final step is the week prior to the event you pick, email the coaches and let them know he will be there and what team he will be on if applicable.
Last bit of advice, look for the schools that do camps with other schools attending. Richmond is one, Princeton and James Madison and Boston College are a few we attended that do. It's a nice way to be seen in a smaller event format.
Hope this helped in some way. Best of luck!