I think that’s where I’m confused, without footswtiches how are you triggering the preset changes?
The XY controller, from the touchscreen of the Graviton or using any MIDI footswitch controller.
Think of the Graviton as a "MIDI control hub" device. You could program it so that if you use anything you want to send it MIDI PC 1, just by receiving that command it could toggle 5 different MIDI capable pedals each to their own preset, bypass states etc. Kind of like what Snapshots do on Helix or Scenes on Fractal. That's obviously just the tip of the iceberg for what you can do.
Could you do that with just a Morningstar MIDI controller with footswitches? Yeah, but you won't have a wireless, touchscreen device that you can put wherever you want and use to program the whole thing, you won't have a little wireless joystick controller you can put anywhere you want either etc.
Above I described how I want to use it to control for example secondary parameters on my Strymons. Since Strymons can also send MIDI CCs on preset changes, I can set the Graviton to track a particular parameter so if I change a preset on the pedal, the Graviton display also shows what that tracked parameter is on the current preset. No more hidden secondary params. I plan to expand this so that ideally I could use it to show preset parameters for a lot of stuff, considering the pedals don't have LCD screens to indicate what is happening in each preset.
On top of that the preset info alone like "which preset is each pedal using right now" is useful. So it will act sort of like a little "what's going on" display.
This will go on a desktop MIDI controllable board and I'll use the XY controller at first to switch presets and maybe later on add a MIDI footswitch thing.
With MIDI usually the possibilities are pretty limitless and it's more about having the right controller(s) for yours.