This is the description of the WAV from the NS Site:
"At the heart of every NS bowed electric instrument is the multifaceted Polar™ pickup system. Developed for the original EU bass, the Polar pickup is really two pickups in one, allowing the player to select percussive and sustained modes. If you were to take a high speed video of a string, when plucked and then bowed, you'd find that it moves in a different pattern. The essentially dual pickup lets you match the pickup pattern with the action of the string. Further, the WAV 4 Bass is equipped with unusually powerful piezo crystals that do not require on-board battery power. "
So it's two, two, two pickups in one? If it was originally developed for the EU series, I suppose it could be wired to enable a blend knob. But is the preamp the same as the EU? If not, might a massive rewiring/parts replacement be necessary?
However, since blend switch is used to blend the mags with the piezo, I have to think blending pizz/arco probably isn't possible or, at least in the opinion of NS, desirable.