An alternative may be setting up a scene widget to the phone’s home screen. Not exactly one touch, or through CarPlay, but may be an option for you.
Another option that might work, in theory, would be to put the myQ garage doors on the myQ app instead of Alarm.com and add something like this:
Then connect those inputs to a Linear Z-Wave or Aladdin Connect Garage Door Controller for Alarm.com. Since the Linear or Aladdin Connect could be controlled through CarPlay, this could be a workaround. Couldn’t say for certain as we haven’t tested this.