Yes many factory race teams probly do use motul oils but 300v we can buy of the self not likely,
6 bar 3000 rpm is to high when the recommended pressure at 6000rpm is only 451 kpa ( 4.51 bar, 65 psi ) as per workshop manual ( page 39 - en-22 ),
the first engine spun number 6 big end which i'd put do to tight off camber corner and the oil pick up drying out but the second one was all 6 and mains and to me thats oil failure,
which was not my point to start with, the point is stock or near stock GTR street driven buy any oil thats full syn and it should be just fine