Let me make sure I understand this correctly.
Within 60 days of receiving the refund, I deposit the refund into the 529, making note on my own spreadsheet that it is a re-deposit of the refund.
In the fall, I pay the QEEs and withdraw from 529 (like I normally would)
Then in 2021, I do my taxes (as I normally would).
Only thing that changes is that I’ve had to do some extra accounting on my end of where the refund came from and that it was deposited back into the 529.