Also the Pg Academic showcase has been scheduled during the SAT subject tests for the past few years, kind of ironic but made it not feasible for many top academic kids.
Good advice on this thread so far. Also FYI HF splits up into teams once the "showcase" part is over after the first half day. Your son gets two games each day (with specific pitching rules and only 5 batters er inning no matter what to speed things along), so he will be sitting around when the other set of teams are playing their games. It is not a great time to talk to coaches during that down time as they are busy with the games going on then. The best time to approach coaches is during a game if lucky enough to have them in your dugout or on the field, or right after the game if lucky enough to have them watching your game (those watching sit behind a screen behind home plate).