I think the possible range for the pitch wheel will be governed by the hardware design. It may be that there is one node on each card to which all the pitch control voltages a summed (from one of micro controller's DAC outputs) if so then yes it could be done. It is unlikely since there are 2 oscillators with separate pitches. Very often the key pitch is feed into a different node to the other CVs, as indeed are the octave cv's. If this is the case the pitch wheel node may simply not provide enough range. Or extending the range may introduce 'difficult to calibrate out' pitch tracking errors. In the end there is flexibility because the CV's are computer generated. But my guess is such a change would require a fairly major rethink of how the P6 manages pitch. Really this request follows on from the need to support the fast developing new market for new controller techonolgy. Such as the Roli and the Linstrument. Here each voice needs to be a separate channel (like proper multi timbral poly mode) but in addition pitch control needs to be continuous rather than in descrete steps like current standard midi notes.