I don't use the active part of my L-1505 either. I'm sure that VVT would sound great. I completely removed all of the stock electronics and now use Master Volume, Pan and Master Tone with no battery at all. To me, the bass sounds much better with my mod. My mod is reversible back to stock but I'll never put it back to stock.
Supporting World Music
fEARful cabinets, Aguilar amps and modified G&L L-1505 basses