Another way to view it: say you get a pay boost 90k -> 190k. The custodial parent will request the imputed income to be recalculated. You now owe an extra 20k PER YEAR. That's your new imputed income, even if you don't get a job like this again and it only lasts a year. Eventually you lose that job and can't find one like it again -- fast forward 10 years. You've paid an extra $200k, just to make an extra 50 or 60k net in one year. You lost $200k by working a higher paid job for a year.

One year of raise followed by 17 years of a slightly more relaxed job at your original income means you LOSE money. In this example, falling from 190k back to your 90k income means child support went from 1/3 of your net check to 2/3 of your net check. A brutal risk to take if you don't think you'll be making the high wage for life.

Strictly no, but this is basically what imputed income does. It's saying you have the capability to earn it. If you actually HAVE earned that amount, it can be extremely difficult to convince a judge that the certainty that you HAVE earned that amount is countered by some vague uncertainty you may not be able to again. Fighting against a known factual salary history with some hand waving about not being able to do it anymore is a hell of a hill to climb. Plenty of anecdotes show people having extreme difficulties lowering child support.