I have a 65 min connection time on two PNRs on a late August flight UA EWR-ATH to A3 ATH-MLO. I know, in theory, the bags will interline. I purchased FASTTRACK. there is a 3 hour later flight, that I was considering purchasing a refundable Y ticket to hold space on the later A3 flight just in case of a misconnect. Any advise thought or suggestions are VERY appreciated.