first off 3,000 a month is alot for childsupport in Wisconsin. Second off, if he is paying CS plus some on arrearages than he has nothing to worry about.
Here is my story
My ex owes over $30,000, I have 2 children and at the beginning of this year the ex was ordered to spend 6 months in jail for failure to pay. Never in the first 19 years was he ever sent to jail. for the first 6 yrs 25% of $0=, than the judge ordered $25 a week for two children for 1 yr, than for 2 yrs the judge ordered $0 in lieu of him 'babysitting' while I worked 2nd shift (I switched jobs after 2weeks to first due to my ex not being able to 'babysit' past 6pm and I worked until 11pm, but it took 2yrs to get it modified) Court order is now $100 a week, but ex claims the only job in WI he can get is as golf caddie and that amount is ridiculus. Ex also has 2 other younger children from 2 other females that he pays $70 each a week to, so therefore the oldest two need to accept less. Ex has now petitioned the court for a modification of $50 weekly, so i shall see when court comes around. Did I mention that ex sees 1 child when he feels the need to (maybe 6 months between visits) the other child he has no regard for.
Mind you over the years there has been several contempt of courts, but none was ever followed through with. As long as your SO keeps making weekly payments and keeping CS informed of his situation, than there is nothing that CS can do.