Hi Aaron,
What classes are you using to build your SDK? From your email, it sounds like you are basing it off the StackMob singleton. I would suggest using the lower-level StackMobRequest class which is parameterized by the HTTP verb and is what the singleton is built on top of. Using that class instead should prevent any need for complex conditional and parsing gymnastics. The stackmob singleton is probably not the ideal class to build an SDK on because it, itself, is the code of the high-level iOS SDK. As for the queue, for the same reason it is not exposed outside of the StackMob singleton, I would suggest your SDK manage its own request queue.