I would definitely try to up the humidity even 10% while he is this young. I keep my adults at 45-50% but I like to keep neonates a bit higher.
While some snakes seem to realize their prey is dead and not constrict, Bci are typically aggressive feeders. I wouldn't be overly worried that he isn't constricting his prey normally, but given the circumstances I wouldn't disregard it either. Snakes go through 2 clear stages and one opaque stage during a shed phase, so it is still possible. As well as just because your snake doesn't seem to be growing like a weed, doesn't mean he isn't, and doesn't mean he won't shed still. Is his belly pinker than usual?
The fact that your little guy is continuing to feed is a good thing. You might want to up the feeding a little bit if he seems like he isn't growing in size or strength, and has a skin hangin' off him sort of look. Sometimes a bit extra humidity and food can help make a world of difference to babies
It also never hurts to have a fecal done to catch any potential problems.