While we’ve played with these endpoints ourselves, until these endpoints get official blessing from SmartThings and get formally documented, it’s not something we would likely formally implement.
And for anyone with the requisite developer skills (HTML + JS), you could create a Custom Tile to use these endpoints as well.
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I would also add that with the introduction of Multi-Device Actions, many people have found that those are as fast as (or faster than) device groups and provide even more flexibility for control.