Many thanks again for the responses LA. I tried assigning the instant access switches and they did trigger either full on or full off on all H9 algorithms, as set by the H9 parameters set to use expression pedal (that is what they are supposed to do). In fact when there are multiple parameters set to the hot switch on the H9 the GCP switches set all parameters to their full on or full off limits, as programmed.
But the EXP still as no response on the H9. So I used Midi Monitor (Mac guy) and got the correct 0 and 127 from the switches as well as 0-127 nice and smooth from both the GCP Exp pedals (I have 2 connected). So the GCP is sending the correct data. The same set-up works just fine with a Vox Tonelab, Axe-FX Ultra, Line 6 M5, and a very old Yamaha voice unit. Pedal does exactly as programmed. In fact just re-assigning the channel lets me access these other units and they work perfectly.