The Homie convention outlines that you can use non-retained messages to process momentary items (doorbell presses, etc).
It appears, based on my understanding of the documentation that those are handled as channel triggers:
System trigger channels are supported using non-retained properties, with enum datatype and with the following formats: Format: "PRESSED,RELEASED" -> system.rawbutton
If something is a channel trigger, is that by definition a 1-way item? For example, in a rule can I fire a channel trigger so that the binding can process it and send it back out?
In my particular use case the momentary button should be bi-directional.