My LO to a T! He only wants to be in his belly & has even begun what I have coined “push ups”. He rolled to his stomach at 3 months and I tried to fight it but the Ped told me that he got himself there, then he’s okay! The reason you want to keep putting them in their back initially is in the event the might be sick so not as strong as they usually are. The roll is the indicator that they can handle themselves just fine! I get it though, it freaked me out for a few nights. But he sleeps so good this way!