Testing to see if GCD is NOT in effect requires custom triggers to make that test effective. Especially for rotational auras, it is as important to know when GCD is in effect as it is to know when it is not.

Adding an inverse/negation option for the existing GCD test under the spells grouping would eliminate the need for custom triggers in the case that you want to know when GCD is NOT in effect.

Currently, when I need to know when GCD is NOT in effect, I'm adding a GCD trigger condition and using a custom trigger to negate it.

No additional context.

Using a custom trigger combination for that seems perfectly fine. It's not something that anyone else has ever requested.