The snag I'm thinking of would be infants, going to the extent of making sure they can't even keep the kids they try to replace the escapees is cathartic and thorough, but dang am I not even remotely sure what infrastructure would be needed to accommodate literal fresh out the womb infants becoming wards of the state. Even with the infrastructure, how do you raise kids from birth without the direct parental figures we usually just take as a given?

We gotta make sure they're safe from their psycho fundie parents, but then we have the problem of probably having to reinvent child rearing entirely to make sure they can enter society as well adjusted as their peers who's parents aren't the scum of the earth.

Also, deprogramming, because odds are that those parents were poisoning the siblings against the child who pulls the rip chord, and associating that kid with "destroying the family" probably won't help that poisoning, kids from intervened families who aren't abuse victims themselves or who experienced abuse in ways that alienated them against the family whipping stool will need special attention to get them to unlearn the hate.