ARCore + GearVR = Inside-Out Tracking?

Hello friends,

I am playing around with ARCore / Handheld VR Template, which works out of the box. (Blueprint)
Now I tried to build the Handheld VR Template for GearVR -> just to see what happens. Result is, that no AR System is detected when starting in with GearVR. (Blueprint)

I saw a super nice Unity Tutorial where they use ARCore + GearVR to have some basic Inside-Out positional tracking.
Possible in UE without breaking my head?

Seems like there is happening alot behind the scenes when running either ARCore or GearVR with Unreal.
Wouldn’t even know where to start digging.

Anyone can point me into the right direction?