Hello. My question is when, if ever, is it worth delaying double tap? For instance, between 20-80 percent, double tap should be used with rapid fire, but what if the CDs don't line up? If double tap is up but rf still has say, 10 seconds left on CD, is it worth delaying or do you just use it on aimed shot? Same question withtrueshot(with unerring vision)?
With unerring vision the best time to use double tap is at the end of trueshot. But if double tap is up and trueshot still has like 10 to 15 seconds left, that would be a pretty significant delay (20 seconds or so) before popping double tap. Is it still best to wait that long?
Use it with Rapid Fire (and delay it if needed) outside Careful Aim, and Aimed Shot within Careful Aim.
Worth noting that you can use it well ahead of time if you know that your next cast will be a Rapid Fire and not an Aimed Shot. You can determine this on-the-fly by checking if (I think it's easier to put it in mathy terms):
AimedShotTimeTo2Charges-CastTime > RapidFireCD
If that is true, you can Double Tap now. There is no need to cast it right before the ability you want to use it on.