Hot take: Feminists' opposition to 50 50 custody means they don't support stay at home dad + female breadwinner relationships
People grow suspicious when you (if you're a man) tell them you want to be a stay-at-home dad in your non 50/50 custody state to protect your child custody
And people grow suspicious when you tell them you want to move to a 50/50 custody state to protect your child custody
But combine them together, and they actually love you: if you want to be a stay-at-home dad BUT you're coming to the table offering your wife 50% custody anyway if she divorces, suddenly you're being a cool customer
So: Feminists DO NOT support stay-at-home dad + female breadwinner relationships, because they oppose shared parenting. You can pull up documents where NOW opposed shared parenting just from the last three years, so they want women as female breadwinners to not have this insurance policy that might sweeten the pot for them and choose the relationship.
(Of course, the full answer is both: outside of 50 50 custody states, SAHMs almost always get custody and support; SAHDs sometimes do, sometimes don't, so yeah, it's about dad protecting his 50% custody too, but that smells like equality to me. Sometimes the court throws out stay-at-home fatherhood, and sometimes it throws out a 50- 50 policy, but it at least has to throw out both in the six states that have it, so that's the best protection for men and their children.)