Emboldened by a recent thread (about using button Hold and Release on HE Dashboards), I went ahead and included a handheld remote device with Device > Button > 3 > Double Tap tile:
And the tile populated the grid just fine:
However, after noticing that the Tile was not functioning (e.g. clicking it didn't execute the corresponding Button Controller rule, the device attributes never updated, and no event entries appeared in Logs), I inspected the Tile and discovered that the "Button Command" field was now empty (no selection):
So I deleted the Tile and re-created it several times to verify this behavior, and find the anomaly to be 100% repeatable. Bug?
NOTE: If I then re-choose "Double Tap" in the "Button Command" drop-down, and click CLOSE, the Tile works fine.
One other minor thing I'd like to mention is that when this Tile gets clicked, there is absolutely no indication (in the DB web UI, anyway) that the click event got generated. It'd be nice if the Dashboard app provided more onClick() visual feedback, such as briefly flashing, or cycling as if depressed/released like a real button.