I've had the same idea, the only other book he's done that went past 12 was Ms. Marvel and it didn't last much past issue 12 and I remember fans having a lot of problems with it. So based on what we've seen maybe long form isn't something he's mastered yet.
It really is, I've said it before but three evil Miles stories in a single run is crazy to me. It would be too many if it was three stories in three consecutive runs and I don't understand the reason for it. There's not really any hard rules for Miles stories right now this should be a prime opportunity to experiment, but instead it's repeated ideas he came up with.