As with most things it depends. For example here in the North East where kids are usually shut down I think at best it's a waste and at worst you are going to get your kid hurt....
My 2020 RHP going into his main recruiting year this past winter planned to start going to college camps the second week in February, but again that was planned from when he shut down the previous season. One school that was on his list had a camp in late January, we decided that wasn't worth it. PBR in NY has their showcases in the end of Feb, and those are feeders for the state games.