With the exception of the big national events my son's team played in 17 and 18 events when they were 16s.
Our experience was the boys wanted the higher competition as the majority of team were already on their varsity teams by that time.
Benefited all of them IMO as the ones who have the talent to play after HS got on coaches' radars early with 4 commits prior to starting their junior years. Several more well into recruiting process.