Can you use a MIDI interface (or some other piece of gear) to confirm that the MKV is sending what you intend, and to confirm whether the H9 is responding to what it's receiving?

From the sound of it, the MKV should be sending a PC to the H9, followed by a CC to the controller mapped to the EXP pedal.  Do those things happen correctly in isolation, when you do them by hand?  As an option, the H9 responds identically to MIDI over USB as to MIDI over the DIN jacks, so you can debug the controls from a computer.  I recommend the program PocketMidi as a bare-bones way to send arbitrary messages.

As a point of interest, do you happen to be controlling your H9 both through the USB and the DIN jacks at once?

Thanks for the reply. I am not using USB. I'm connected via midi out on the EFX to midi in on the H9. 

The program changes are working and the range command works but the Beginning Values (which are CC as I understand) do nothing. If you look at the attached file in my original post you can see how Musicom allows for settings relative to the expression pedal. It does take the min/max values. The programs change properly. It's these deeper settings that aren't working right.

So, to be clear, the expression pedal works correctly once the preset is loaded on the H9 when you start moving it?  Do you have the CC channels and numbers in this configuration set to the same channel as the H9 and the same CC number as the EXP_PDL channel?

Sorry, I'm not familiar with MKV and don't have access to one at the moment, so trying to reverse engineer this from the MKV manual.

It would be very helpful to be able to bisect this problem by looking at the messages between the MKV and the H9.  You don't have any way accessible to you to do that?