The paulxstretch completely obliterates phase component of audio input. Its not really way to do it if you want real output.
Phase is relative, you are trying to sound intelligent
As long as you match the phase of the positive and negative frequency components you'll get real output
Doesn't phase only matter if you want to mix it with some other sound? If you're editing the final version you're going to be playing, what's the point in preserving phase?
Define "real" in this instance? We're talking about audio manipulation, fiddling with time and frequency domain. Something's going to have to give