Something to consider:
This track has a number of corners that are heavily painted near the apex. The kart actually seems to understeer off corners that are not painted. Most of the oversteer occurs coming off the painted corners. As the heat goes on, it appears that you are consciously (or unconsciously!) adjusting to those corners by slowing through many of the painted sections and “straightening them out”. I agree that the new tires may help considerably and moving the rears in slightly should help with the oversteer but I’d be curious to know how much oversteer remains on an unpainted apex with newer tires. Also, I wouldn’t waste much time trying to dial in handling until you change the tires. Agree that narrowing the rear would be my first change if oversteer remains. Best of luck.
