Not this car seat - but the one I have the newborn insert is based on babies height in the manual. So two years ago my little girl was 4 1/2 months when that height, my little boy is only a cm off at 6 weeks 🤷🏼♀️ so definitely worth a check
I think it said to remove it once they were 58cm from what I remember but it was on the back of the insert. I had to take it out to see the guide
Thank you!!
Ideally it’s supposed to be left in for as long as possible and on average is removed 4-6 months. It’s not just for their heads it’s for their leg and side muscles too. They may look snug but if he was uncomfortable he’d be complaining, snug is safe. There should be weight/length restrictions in a manual or something to confirm xx
I did remove mine quite early… you could try it without and see the fit