You are correct. The game does have separate casting & release animation.
I’d concur it’s a good excuse to reintroduce Aero III’s release animation considering how they both has the same floating casting animation. All that’s left is to replace the Cure/Regen release animation into the good ol’ cane twirling animation.
But I’m sure somewhere within SE are screaming “Aero III is just a fever dream. It’s not real. Forget about it pls.”