I figured they would refund.
It does bring an interesting issue for a small pool.
https://pool.laurentiapool.org/#/workif this small pool had hit it . the software auto sends to the four addresses that have mined to it.
so that 25 coin block would go to four people. take 180 blocks to clear. and paypal/paxos would need to talk to four people to get a refund. not the pool but the four that mine to it.
I live in U.S.A. I would not be able to simply return the 7 or so extra coins I got. My address is registered and is kyc. thus it would look like I had a large taxable income.
Actually, no miner has to refund any transaction fee, even if it's 1000 bitcoins, simply no miner has to do that because there is now limit to bitcoin transaction fees since it's dynamic and fees are set manually from 1 to infinite, as you wish. So, I assume no one can force any miner to return transaction fees, it's absolutely your kind will to refund it.
To be honest, asking for refund of transaction fees looks like asking for refund of bitcoins that you sent to wrong address. If I send bitcoins to wrong address that doesn't exist, who is going to refund? This is nature of bitcoin, so, your wrong transaction fees should be taken over like wrongly sent bitcoins or lost bitcoins.