Maxi cosi rock car seat question

[Autumnalfeels]

Hi, so my little one is 3 months and his head is nearly passing over the infant head support... I'm just wondering, has this to be removed? Surly I will have longer out the car seat than 3 months? Does he then just sit in the car seat without anything else or so I need to buy another insert?
Sunday morning brain fog where I have no idea what I've to do and no longer have the instructions lol

Thanks in advance x

My lo is 4 months and I've just removed the infant head support not using any insert now.

The instructions are online here.

They suggest removing the insert once your little one reaches 60cm. After that they need less support :)