I'm pretty sure the cooldowns are popped whenever possible, unless waiting for 1 gcd will result in a better output.

For example, BFB goes off cooldown after you used True Thrust, waiting to use it after you use vorpal thrust will result in better output.
Best time to pop BFB is posted by Dervy in first page.

So far I only got PS and Jump timing down because it's very simple lol, 2 jump = 1 PS