I made a very good living for 30 years with emphasis on thermal design
Either the card needs the cooling or not. If it could have been engineered to have a passive cooling scheme or minimally noisy low rev fan it should have been done. We are talking a $6000 card right
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Whether the OP has truly tested all the worst case use scenarios (or understand how to extrapolate from IC case temp to internal die junction temp) is unknown but certainly a bi state fan is bush league....