Subscribing to OnUp event to drag + move object

I've looked over the VR samples and read about interaction for the Gear VR, but I'm struggling in subscribing to the OnDown and OnUp events. Based on the ExampleInteractiveItem sample, I can carry out actions when the button is clicked, but I can't see how to do something on the OnDown and OnUp events. I can only see how to do it within VRInput.cs as part of CheckInput() for CheckInput.GetButtonDown / Up

I've seen a few other posts that didn't really get an answer so that when the raycaster...

Subscribing to OnUp event to drag + move object