I may be mistaken, but it looks to me like this device type handler will allow the puck to be added to the SmartThings network so it can then independently control Tradfri bulbs that are connected to the same network by talking to those bulbs directly. But it doesn’t look like the puck is sending its button presses to the hub, so you would not be able to use it to control any other SmartThings control devices or to change modes or anything like that. That is, it’s not acting as a button controller like a minimote. It’s just able to control some of the same bulbs that smartthings can control.
So the puck becomes a parallel means of control, but it wouldn’t do you any good with webcore or SmartLighting.
If I’m wrong on this, hopefully someone will let us know.