so stressed about car seat, ds too big?? Is this unsafe?

[urghl]

It says for the one we have it’s max 85cm height, up to 15 months. Ds is 9 months and already 92 cm and I am so worried he’s obviously been in it while too big, will that have harmed him?

also can anyone a understand if these two car seats are different? They are wildly different prices but look the same? I am so stressed.

https://www.halfords.com/seasonal/child-motoring-safety/joie-i-spin-360-group-0plus%2F1-baby-car-seat---coal-806924.html?

https://www.johnlewis.com/joie-baby-spin-360-group-0-1-car-seat-ember/p3975674?deepLink=false

We have the i spin 360 and when my eldest was your child's age I had similar concerns about him being high centiles and growing out of it before he could safely move to a high back booster, but actually his growth significantly slowed once he hit 2, and he didn't grow out of the seat until he was just over 3.5. Now using it for our second child.

It's been a great seat for us, I've really liked it!