Hello
We don’t expose the Inc, Dec or other custom events at the moment.
There’s a bug report you can follow for this if you want to be notified if there’s a change on this:
EnumerateInputEvents doesn’t return _INC, _DEC, _TOGGLE, _ON, and _OFF events - Bug Reports / SimConnect - MSFS DevSupport (flightsimulator.com)
Regards,
Sylvain