I get what you are saying but if you always use dualcast with the long spells wouldnt it essentially make the fire and stone spells seem more underwhelming, having to hardcast it and have lower damage than the thunder and aero spells.

Maybe i wont even notice it since you are throwing two spells at once. I think if dualcast also lowered the gcd flr that one cast so you didnt have that delay to cast the next spell it would speed up well. I just recall on my scholar hating to hardcast miasma and bio2 then waiting on the gcd for aero and bio1.

That also being said the slight delay can fit the ogcds and see of the stone or fire procs happen or if you are gojng to jolt or impact.