This is a timely thread, as I have very recently been debating on adding my HX Stomp XL to my FM9 for a little more, well, more. What I’m contemplating is adding it to loop three in the FM9, and using it for drive pedals and a couple other front-of-amp effects. Partially to free up some CPU, and partially to add some of the Line 6 flavors to the chain.
MIDI implementation would be stupidly simple for what I have in mind, basically just PC messages from the FM9 to control presets and CCs for Snapshots in the Stomp.