So I just did an experiment with biz fares on JFK-LHR. There are currently biz fares with a $400 fee for refund (the fares ending with a 3 in fare basis code below) on this route. The ones ending with a 9 are refundable with no fees. I did a roundtrip fare search for April on aa.com, and I got the INN4I1S5 non-refundable fares when searching with "Lowest fare" option, and the INX8C3S9 refundable with no fees fares when selecting "Flexible fare" search option. So at this point in time, selecting "Flexible fare" search looks to skip over the refundable fares with a fee for refund and only shows refundable fares with no fees for refund. Note that EF fare listings only show base fares and don't include carrier-imposed fees or taxes (which is why the roundtrip fares below look so low).