To clarify I'm talking about firestarter and thundercloud procs yes they are insta cast but they trigger the GCD.
Normal casts: 2.5 second cast time then cast next ability
Insta cast : cast straight away but wait 2.5 secs for gcd

Basically what I'm saying is I think these procs should not trigger the gcd, as the advantage gained is nullified by waiting for gcd.

any thoughts?
Am I asking too much?
Any alternative suggestions?