Even with Pitch Correction selected, many of the voices go flat over time.
That’s realistic, but not always a desired behavior.
As a result, I find myself manually rewriting the Pitch Deviation curves, or adding a Pitch Correction VSTi to the vocals.
Adding a Strength (in cents/milliseconds, perhaps) option the pitch correction would help the Pitch Correction behave in a more standard manner. SynthesizerV already knows what the target pitch is; if just needs to apply a constant correction per timestep to the pitch as it deviates from the center pitch.
Hrm… On consideration, it seems like something that should be scriptable… 
Still, it would be nice as a built-in feature.