If you don't force a crossover then DVZ takes over and randomly
chooses appropriate crossings for each string on each instrument to
produce maximum sonic variation. You can also switch between vertical
bow positions such as Sul Ponticello or Sul Tasto, and continuously vary
between them with a slider. All of these selections can be stored with
automation (editable using MIDI CCs).

String players intrinsically play nearer to the tip, middle or heel
of the bow based on the speed of notes played and the desired intensity.
This is because if they want to play forceful notes, they need the
leverage of playing near the heel (frog) of the bow. If they must play
agile, fast notes, they need the “bounce” at the tip of the bow, which
also limits the amount of pressure they can apply to the strings. DVZ’s
Auto Bowing does this for you based on how you play. This is another
reason 70 DVZ strings sound so natural with any playing style. You can override automatic bowing by pressing the Heel, Mid or Tip Bow buttons.

