This what Strymon people told me:
Thanks for supporting Strymon!
If the H9 can send MIDI PCs, then you are able to use that to recall presets on the Sunset. you will need either our MIDI EXP cable or something like the Empress MIDI box to go from 5 pin DIN to 1/4″ MIDI.
Every MIDI PC corresponds to a preset on the Sunset, for example PC 0 is the first preset, PC 1 is the second preset, etc.
https://www.strymon.net/manuals/Sunset_UserManual_RevB.pdf (Page 15 is where the MIDI index starts)
The manual will walk through how to set up the pedal to accept MIDI via the EXP Jack. Remember to make sure it is on the same MIDI channel as your H9.
Let me know if you have any more questions!
I would say that is not possible beacause as far as I know you cannot control that midi codes by means of the H9
Tell me if I’m wrong.