What about the apparent change in gravity due to flying westwards/eastwards at 450kts?
Do you mean the gentle decrease in the reaction force from the floor because you're following a curved path at speed? Which would also apply the same if you were going north-south? At 6000km radius and 300m/s that's about 0.15% of g.
Or are you worried about the relativistic corrections to timing, which are down at the 1 in 10-to-the-10 level, or the difference in co-rotation and counter-rotation terms in general relativity, which are stupendously small on scales of the Earth size and mass.