457 to lower AGI/IDR

So I am considering maximizing my governmental 457 plan contributions to lower my AGI and thereby lower my IDR payments and basically following this path until my PSLF date to minimize payments. I received a raise last year and am trying to keep monthly payments to a minimum until forgiveness.

I want to do this when I recertify this July instead of relying on last year’s taxes; however, I keep hearing that if I provide a pay stub, even though it breaks down my benefit and tax deductions in detail, they will just use my gross income.

Therefore, would it be worth maximizing my 457 leading up to recertification so as to reduce my AGI, or will they disregard my deductions and just use my gross income? For example, would they derive 10% of a $10,000 gross monthly pay = $1,000/month IDR payments, or 10% of $7,000 net (post-tax and -benefit deductions) monthly pay = $700/month IDR payments?

Has anyone got personal experience with using pay stubs for IDR recertification, 457 or otherwise? Any insight would be much appreciated.