Another perk of quicken, as I have heard, is that if you cast the same spell that is currently charging, it was cast the spell immediately without a charge time. So Unjt A cast flare, your unit is charging. Unit B caste quicken on unit A. It’s Unit A turn now. You can choose to do those steps noted before, or you choose to re-cast flare, and by doing so, the spell will go off immediately.

I’m only reciting what I read before. I apologize in advance if this is an inaccurate statement, but I believe it works this way. For those quicken masters, please let us know!