I hear that; 2 a day was common in the T-34 aerobatic/PA stage, and S. TX was damn hot.
G's in the T-45 have not been an issue for me, and the G suit helps a lot. Not sure if the O2 helps out at all, but maybe. I did start to grey once coming into NGP with Kmac at the controls doing a short break, but I think that was cause I doing something and wasn't prepped for the G's.