No, I think I can pretty much guarantee that this is nothing to do with the Audya delay.

The Melodyne2 process is NOT a realtime function. It takes time to analyze the file, and then it takes time to process the file. On even the fastest current computers, Melodyne's own demo shows it takes several seconds to process a very short file. So this rules it out for current arranger operation, where the CPU has got to do a whole bunch of other things, all at the same time... (and couldn't do it realtime even if it WEREN'T)

Maybe in a few year's time, when CPU horsepower and speed ramp up another power of magnitude or two, but right now, even Melodyne can't make this realtime...