Fairness in Child Support

There needs to be guidance from the federal government to the states on how child support is calculated, now that we are in a time of shared parenting. States mostly have outdated methods of calculating child support based on custodial and noncustodial parents. Where the noncustodial parent would pay the custodial parent.
The Federal government now needs to expand on 42 USC 667 and title 45 vol 3 sec 302.56. to include language on shared parenting.
302.56 does mention states may take into consideration custodial parents income in the calculation, but it does not go far enough.
Like I have mentioned above, state methods are based off an old model. Fore instance in my state if both parents make the same amount each month, with 50/50 shared custody using $3,000 per month of income for each parent. A child support payment of $534 needs to be made, leaving one parent with $3,534 to support the child and the other $2466 to support the child in the same manor. And then with the child wanting to be with the parent with more income to support them, and their needs. I've talked with the state office of HHS and they say they are only following Federal guidelines.