so, it turns out turning the latency down corrects the problem between the render and the playback on the device. this only makes sense if the render is occurring at a lower latency level than the playback. what it means is that i was rendering without full use of the plugins. but, oddly, the plugins sound better that way on playback, too. i'm kind of left to conclude that the plugins must have been engineered to work at a lower latency level, and the logic i was using (more cpu power = better quality plugins) is not correct. rather, i seem to have been sort of overloading them, asking them to calculate more accurately than they were meant to and getting a weird result out of it.

realizing this makes the process a lot easier, although i'm going to have to deal with the odd crackle and pop when i'm mixing that will go away on the render.