Enhancement: garage door venting
I am attempting to open my garage doors approx 12” to vent during the hotter months.  Certainly HomeKit doesn’t have provisions for this, but possibly via MQTT?  I have a native myQ garage door plus an older chamberlain which has been added onto, so I am testing two different implementations. 

Using the low voltage wall button, I can press to begin opening and press again several seconds later to halt opening. I cannot reproduce this via MQTT, the opener will not respond to additional commands until opening is completed. 

Is this expected behavior?  Can this be worked around?