Coparenting Issue

Minor issue, but I’ll keep it short. My ex and I share a 15-year-old child. No child support is paid. I have primary custody with final say over medical decisions, and the court requires me to carry health insurance for our child. My ex isn’t required to carry insurance but does anyway.

The issue? His insurance isn’t as good as mine. He refuses to use my insurance, and his higher copays and lower coverage mean we end up splitting bigger bills. For example, his insurance might leave a $100 balance where mine would’ve left $25, costing each of us $50 instead of $12.50.

On top of that, I have no access to his insurance info, while he has full access to mine (cards, permission to call, etc.).

I feel like if I’m paying for the insurance required by the court, it makes sense to use it as the primary coverage and his as a backup. Am I wrong for wanting this?