I have just had my question answered via a search of other discussions on this site ........... and I don't like the answer one bit.  So Line 6 can get away with advertising a USELESS product  - the Ex1 expression pedal.  The product spec says it is designed to be compatible with the FBV shortboard to permit separate volume control.  I spent £45 buying one specifically for this purpose and it DOESN'T WORK (except to duplicate the shortboard pedal function).  It is not good enough to just say "yes there is a functionality problem".  It seems a lot of people on here are in a similar position.  Line 6  ought to at least recompense people who can provide proof of purchase.