Malev Hungarian just matched my BMI Gold to Duna Club Gold (OW Sapphire).
Emailed a copy of DC card, and a OW boarding pass stub. Showed as Gold within a few hours.
Nice way to get BAEC perks, given my BA travel patterns (mostly EDI-LCY in cheapy economy) and their stingyness (5 tier points per sector), I will probably never even reach Silver.