When my aunt and uncle knew that they had a lot of friends and relatives of other religions who would want to celebrate with them but would not feel super-enthusiastic about sitting through a whole church service, they arranged for their kids to be baptized privately (that is, with friends and family but not as part of the regular service). I am not RC and don't know whether an RC priest would agree to that, but the Protestant hymnals I've experienced have baptism services written as though they can be held as entirely separate short services even though people mostly don't use them that way, they just fold the parts into the regular service that aren't already in it.

But yeah, coming into church after an hour and coming up so you got a good seat to see the baby being baptized would be considered pretty crass in my faith tradition.

Also, most of the Protestant baptisms I've experienced have been toward the beginning of the ceremony, so the idea that it would come at the end when everybody had already left is educational for me, thank you for expanding my knowledge of other denominations a bit.