i finished it now with my new chocobo. was very lucky with the breeding, to get all 4 stars is still very random for me xD i tried your build with 500 Speed, 395 Accelearation, 355 Endurance, 500 Stamina and 500 Cunning with Incrased Stamina 3 and Chocobo Vita 3 (can't change Increased Stamina 3 so easily). it still was veeeery hard. i was faster than max power, but i ran out of stamine before i reached the finish line. so it took while until i had perfect weather, did not get hit from everything and got a potion from a chest... far from 95% win rate, but doable.