I don't see there being any orphanages, you could simply have babies on demand for anyone who wants to adopt them. There are enough couples with fertility problems, women who can't carry a pregnancy to term for medical reasons, etc etc. The adoption process is currently unworkable: couples will routinely spend tens of thousands for a chance at adopting, and the birth parent can reverse the adoption at any time and you've simply set a five figure sum on fire.

You could also incentivize couples to adopt up to the point that the (augmented) fertility rate hits replacement level. That's the ultimate problem to solve here, you're not trying to grow the population, simply put a floor under it to stabilize and prevent demographic collapse.

With how little we prioritize education versus other things it’d be a disaster. They’d be factories for neglected and traumatized children who would have a high likelihood of growing up to be criminals or homeless.