User Action Event Handlers, like most EH types, have the _thisEvent special variable available, which contains information about the event type. However, for User Action EHs, _thisEvent only reports half of the event type - whether it was an Activate, Deactivate, or Analog event. It does not report the input action the EH was associated with. It would be useful to have this available in the EH.

Unfortunately, _thisEvent is already taken up by the state type, so I'm not sure exactly how it could be reported. Possibly by adding it to the params array....or maybe it's OK to modify _thisEvent into an array of [_stateType, _inputAction] since it was never documented before. Or maybe _thisEvent2, but that feels dirty.