Keeping in mind that 1099-Misc box 7 is now 1099-NEC, and it still only is issued by a business, when their total payments to a person for services reaches $600.

So, first, your taxpayer might still have independent earnings from weddings, etc. Not reported on a 1099-NEC doesn't mean never happened.

Next, if the related expenses are associated with a W2, you have an employee. It doesn't matter the justification or the amount for that additional payment. It's all "as an employee."

So you treat it no differently than any other possible State deduction, but not for Fed. It's not just his "addition" because it's all the same pot, now.