Is there any way to determine whether our refund form was submitted correctly with the signed message... or... do we just blindly wait for a refund and hope it appears in our wallets?
Good point, but to be fair, separate confirmation requires more processing on Steamboat's side - he has to process hundreds of refunds manually. People will post on this thread once refunds start coming in - if you don't get yours and there has been no further communication from Steamboat, you should probably get in touch.