This idea has 2 parts. The first part is independent of the second part:
Disable a Message in the Editor. I think it would be useful for testing complicated presets when you just want to remove 1 Message quickly, but leave it in place in the Editor Preset.
The second part is clearly way more involved than the first, but depends on it: If disabling a Message still meant that it gets sent to the device in a disabled/enabled state, then a new Type that could target a Preset and Message in the same bank to enable or disable that Message would be pretty nifty.
Here is 1 example how that could be used:
Controlling an Audio Looper over MIDI, the Audio Looper supports multiple tracks, I program one switch to manage “Track 2”. The first time I click it, it places Track 2 into record mode. Then that Msg is disabled and another Msg, one that Plays Track 2, is enabled. Subsequent presses on the same switch will only play Track 2. That makes it different than the Toggle feature, it’s not a back and forth. It’s the ability to add new controllable states to the Preset that have persistence.
I suppose that instead of adding an “Enable” bit, you could instead add “None” to the Position enum and then make the Position variable controllable via a new Type, though I thought that might get a little hairy.