I've been playing a bit more with it and there are also some crackles that appear randomly. It's not distortion, because they occur at low volumes as well as at high. They occur in patches with as few as a single oscillator set to a lower level < 64, so they're not internal clipping, and they occur more frequently with the delays active than not, but that's not a correlating factor either as they also occur without the delays. I need to do some more diagnosis before pinpointing the source of the issue, but it's definitely concerning me.
I'm also finding that patch design is suuuuuper picky, there are far narrower sweet spots on this instrument (at least so far) than on any of my other synths, but the workflow is fantastic. End of day, though, I'm still on the fence as to whether this is a dud unit or I just don't like the P12, made worse by the fact that I have no idea if this unit is actually acting correctly (due to all the other things that are wrong with it, the voice behaviour is also suspect to me).