Let me put this another way.

He thinks that because he takes the kids two nights a week you should bill 24 hours freelance labor on those two days and have NO OTHER DAYS OFF all week while you provide childcare and homeschool. Is this your understanding? If so, not reasonable.

You don't have to bill 24 hours on those two days so he can reduce his child support or alimony. His choice to leave, his financial risk. You don't have to fix it. You could decide to get what the law allows whether he likes it or not. THis may sound harsh, but you can't have no days off per week.