Palettes

The palette does not currently save a preferred inversion/voicing per chord. That's because the palette (and Harmony in general) is meant to be used by all instruments at the same time. 

But you can collect Harmony parameters with particular inversions/voicings in a library. Inversion and voicing is stored with the Harmony parameter. Each chord segment in the Figure parameter may override this if Interpretation allows (it has a check box for that). 

If Interpretation has a guitar tuning selected, it should prefer the grip pattern that was last selected on the free floating fretboard widgets. But I'm not sure. Even if it works it is not practical because it depends on a global state not controlled by the arrangement.

The most reliable way to ensure a particular voicing/inversion is to select it for each Figure segment exactly where you want it and enable it in Interpretation. This way a guitar can play a different voicing than the keyboard, or the strings, for example.