I often leave them in - although I think the makers generally recommend removing them to reduce stress on the snaps. Mine have never pulled out, though ...
ATM I unsnap them all as Alastair has horrible stinky toddler poo and I want to make doubly sure everything's agitating as much as possible. I never bothered with breastmilk poo
What kind of nappies are they? I know some OSFM like BabyBeehinds are designed to be used without at least some of the boosting on newbies. If they're sized I'd just use them as they are and see how you go. But then bulkiness doesn't really bother me
Oh, and welcome to NC! We do have a Getting to Know you section as well if you want to tell us a bit more about yourself