No SDK sample for Mobile native activity + controller input & rendering?

I'm a bit lost on how to proceed here.  I see a VrCubeWorld_NativeActivity, which got me 75% of the way using my engine with quest, but now the VrController is way too high level for me to use.  I need to know how to use low-level code to get controller positions and (nice to have) a way to render tracked oculus quest controllers for the user.  

Anyone have any material on this?

Obligatory statement that I'm not using Unity, or anything high level at all.