I ordered a pair of boots from Mexico, they were shipped with all of the correct paperwork and should not have been tariffed at all. It added ~$60 to the original cost of $170.

When you submit a tariff refund request they warn you multiple times that if your submission is rejected you will be charged $100 per submission. It can be rejected for making a mistake on the paperwork even if they find the tariff was applied incorrectly. I almost didn't submit for it, and a lot of people won't but I decided to risk it. That was a few months ago and I still haven't heard back.