Hello Ksy, and yes you have the lingo down
Yes, my DS used to jump more, when really into something or excited. He still does it occcasionally when he is on the computer for a bit or doing a task that takes a while and he has to be still, then he will randomly get up and do it and then sit back down. Honestly, I think they are little and their bodies are active and their minds are active. DS5 still spins some randomly. This is sometimes when he is bored and unsure what to do. He started doing it really early (like before 2). Everyone has seen it some, even the pediatrician, but they are not concerned. With the spinning DS does notice he is doing it, he just thinks it is fun. I think he is looking for some vestibular input or something, can't quite figure it out but he enjoys it at times. I guess some of these things come and go...he hasn't been doing the flapping thing since I first posted here. Very strange.
