So kids are just genetic freaks. My daughter had a BHS at 3 and now has a perfect double and std full at 8. I conditioned my daughter from the minute she was three and didnt let her flip until she had the check points I felt would enable her to progress safely. When she could do the skills I felt were necessary and clean I let her try and she got the BHS is a couple days because her body was prepared. I have kids who are 17 in my gym and their bodies are not prepared to do a BHS. So I understand the whole body developing thing but if you have the core strength and other bio mechanics needed to perform---I say go for it. I allowed her to do them first off a 2 ft high mat in to the pit and progressed her to doing it off an incline mat in the pit then moved the incline to the floor and progressed her down it.