Scott,
90% of the time, if I'm playing manual bass.... I have NO auto accmt playing. The Korg allows you to specify which hand triggers the chord, so setting up the design you mentioned is a snap. I constantly swicth to right hand recognition in the middle of a song, if I need my left hand to do something like search for a business card, or turn pages on the LapTop....whatever.
The 2100 has the left hand set to bass, and the right hand on a chord sound....no acc used. (not possible, as you've discovered)

I love the flexibility that the PA80 offers, even if the learning curve is so steep. I access the "Bass to lowest" from a dedicated button, the "right or left" hand triggers , and much more.
These are some of the reasons that I put up with the awkward drum fills. I try to avoid the really stupid ones.

Playing bass is still one of my favorite ways to perform, so I use it as much as I can....with no arranger. Just left hand and right hand making the arrangement that I sing over. It brings me the most satisfaction, and sounds just wonderful in a more intimate setting.