Gear VR touchpad support

I have noticed a very interesting thing while viewing 360Cities on the GearVR/S6 (GearVR Service disabled; ordinary Chrome browser): horizontal swipes on the HMD's touchpad pan the view, stably.

1) This is a terrific feature and I want to enable it in my stereo panos. Can anyone show me how?

2) My happiness would be complete if I could also capture vertical swipes and use them to control zoom. Is that possible?

Maybe not documented, but actual anyhow. I think we should try to track down how it is happening. There are lots of odd connections inside Android.
I will do a bit more research to see if I can delimit the possibilities.