The court in the father's still-unidentified state of residence will calculate child support based on its own laws and guidelines, not those of Michigan.
Mom has established residency in Michigan.
Why would she start in the ex-husband's state? Why can't she close the Chinese order and start fresh, petitioning for child support in Michigan, where she and the child (a US citizen) have residency, and have Dad served wherever he is?
If the jurisdiction is established as being where the father is, that's also going to be where custody/visitation end up as well. (What? Dad's been paying a pittance in child support. He might suddenly develop an interest in his "investment" if he has to pay more.) This could be very inconvenient for Mom.