We've got the graco and it's said when the little one is 60cm x
Your manual should have the instructions included on size by height, often you can make small adjustments before removing entirely x
They're often 60cm. My girl was 59 last time I checked so I'm planning to remove it soon!
Yes we’ve removed ours, but baby girl is 64cm tall and 14.6lbs already
Mine is removed and I just judged whether she looked big enough to not have it in anymore