If the focus is D3 no issues with timing. If your son is a position player with a solid glove and a big bat, he won't be late for D1 HA. Regardless of which camp your son attends he has to be prepared to show his stuff.
My 2018 went to both HF and Showball Camps. Both are quality showcases run differently. Showball is faster paced, the coaches are very involved in moving it along. They know what they're looking for and don't need a billion looks at a kid.
I would do the Showball Showcase in front of the HC's in June, then maybe the HF Camp in late July early August.
What position does he play?
Which D3 schools is he highly interested in?
Right now is a great time to prepare video less than 2M and send an email directly to each of HC and AC's. While they are busy with their seasons, they're addressing emails by day and while being on a bus to games.
My son hoped an Ivy would work out, landed at D3 HA NESCAC where he's very happy. PM me with any specific questions you may have, happy to discuss over phone as well. Cheers