I did use the pop in for night time, when my daughter was few months old. It fitted well at the beginning, didn t have any pb, but after a while, it was a bit small as the nigh booster makes the nappy bulky. Then, I used the booster in a bamboo nappy with a wool wrap. She is now 14 months old, still works fine if she doesn t wake up too much for a feed during the night, and while I fund some more WNNN or a sewing machine.
The pop in are too small now for her, it is a pretty small nappy for a BTP!