Hi, I'm NOT authorized to speak for Presonus but they will never do this... I suspect that you haven't read up on the link channel function? In section 4.1, page 29 of the manual you will see that you can ONLY link even # channels (internally) and that the right fader of the pair will be the "balance" control between the stereo pair of channels.
FOOTNOTE: A popsicle stick cut and laid across the two faders works well for this...