You're really throwing anything you can against the wall to see what sticks. You have alot of "ifs" here.If there is a large enough disparity of income, then he could be primary custodian and still have to pay some child support. It hasn't been determined that either is primary custodian, they have shared custody. She can be imputed a higher income as you mentioned, if that is just minimum wage it would still be much less than his income.
And "if" he is providing the primary insurance, that is considered "support" in many states, therefore lowering the amount of support owed, "if" any.Assuming her ex has an attorney or the knowledge to ask that a higher amount be imputed based on what her earning capacity is, then their incomes could be more equitable. I did say based on the incomes she provided he probably would have to pay. That part was not a given, but the medical and discount for overnights are spelled out directly in PA guidelines.
And he would have every right to protest that and ask for more time to decrease the need for daycare and inflicting additional expenses onto both parents, which would give him more time than Mom.And childcare costs would be considered if she needs to get another job, they too are shared by both parents.
Or mom can simply agree to have a respectable income imputed onto her for being voluntarily being under-employerd by being a SAHM (since so many make the argument that it actually is a "full-time job"), so there is no support being exchanged. BTW...there is no discounting the responsibilities of being a SAHM, but if one's going to make the argument of what a full-time gig it is, then those who do should agree to have an income imputed to reflect that. And not minimum wage, either.