So I can get useable results from the Kurzweil CC-1, Behringer FCV-100 & Korg Exp-2 (thats all I have tried so far,). The Global settings menu has a handy polarity selection option. My biggest problem seems to be that there is no global settings option to assign the pedal to control volume control. Using a CV pedal to control volume requires creating modulation slots at the program level. I have posted a more detail explanation in the firmware improvement request thread.
Expression pedal control of filter cut-off, which can be easily selected at global level, is wonderful - feels much more natural and expressive to me than than turning that big knob, but perhaps thats just because of my organ dominated background (ymmv) .