I think the vast majority of seats fit. I had the kiddy evo lunafix (the lie flat one) and a maxi cosi that we used for travelling. Didn’t have the Peach for long though as really didn’t get on with it but you shouldn’t have any issues with the car seat.
It's bad for your baby's spine to push them around scrunched up in a car seat, and there have been studies showing that the amount of oxygen in the blood drops after 30 minutes in a car seat. Children have asphyxiated because of being in car seats for too long. If you have a proper lie-flat pram why not use that and leave the car seat in the car?