Would you consider sending them to an Islamist school and then humming and hawing about what you would and wouldn't have a problem with?
Quite rightly, they'd tell you to take a hike.
If you went to a vegan restaurant, knowing it was a vegan restaurant but went because it had a Michelin starred chef, and demanded a steak-they would-again-show you the door,
The clue to the school that you want to send your children to is, amazingly enough, in the name. It is a Catholic school and they will teach the Catholic religion and can do without cherry pickers attending.
If you are that precious about 'issoshes' that you have the gall to say you would be offended by, if they didn't approach them in the way you see fit, then don't go.
Ridiculous, entitled, and ignorant attitude that expects the tail-you- to wag the dog!
I do hope that if you do have the temerity to send your children to a Catholic school and then expect them to teach your beliefs, that they tell you to gather up your children and piss away off!
Hope that helps to clarify your silly, foggy, hard of thinking process. process!
I do so hope that helps to clarify the issue for you.