but using up a level 7 spell slot for 2d6 damage per turn is perhaps not the best idea. Not the worst either, it adds up to quite a lot of total damage per cast.
I'm not really in a place where I can discuss this since I'm only theorycrafting but I already took improved abundant casting, slots aren't really an issue imho. I'll be better informed once I get there but my idea is to use it to neuter the chaff and inflict some damage on everything on screen, exhaustion is nothing to sneeze at and, contrary to what the resident expert said, a number of scary entries in the MM are actually susceptible to it.
Edit: also you can scribe scrolls of selective sirocco and leave your precious slots for other things, if you're so inclined!