On Transition Only was added in August:
Note that this did not change how any existing triggers are evaluated. We improved some of the language to help clarify the difference between what the triggers are actually doing, but there was no functional change for existing rules.
That being said, if your driver changed or the behavior of your device changed and it started emitting multiple events where it previously only emitted one, of course that would have a functional impact on your rule’s execution. And it’s one of the use-cases covered by the ‘On Transition Only’ option. 