@Wayne-TP 

Mostly, yes... but after a lag... by the time my double tap kicks in to silence a panic alarm, set for a 5 sec alarm duration, the alarm has stopped already.

Also, if I try to create a new automation that uses a double tap, I get a message saying the double tap us not enabled, when it actually is... I have to disable double tap and re-enable it in order for the creation of the automation to work.

So I could say the double tap feature is "buggy" 

  @Wayne-TP  no, that definitely wasn't the case for me - the app seemed to be displaying the changes almost immediately, but only when the changes actually were being applied by the smart action.  Whilst I was having other app problems (the "invalid triggers" issue noted by BPCS), I would have to say that the app was doing a good job of indicating the true state of the system that day, it was the system failing to change state in the first place in response to the double taps that was the real problem.