Quite surprised about this:
I wouldn't have thought that there was a lot of difference between
(a) taking the piezo sound from an acoustic guitar, and from that producing the fully miked sound of that instrument, and
(b) taking the piezo sound from an acoustic bass guitar, and from that producing the fully miked sound of that instrument.
(I know that would mean Fishman developing new 'images', and existing pedals with acoustic guitar 'images' wouldn't work with bass, but even so ...)
Maybe that wasn't the question you asked them ? (Or maybe my guesswork about what goes on in an Aura is way off the mark)
Andy