Gear VR input for 360 movie player using two cameras in two spheres

I have made a 360 movie player using two separate cameras for left and right eye within two spheres.

I have also followed the VR samples to setup input for projects that only use a single main camera.

My problems are the following:
I want to use gaze or touch input within the movie player to eg. change frames etc. Now I wasn't sure how to handle this case, so I just tried to attach the UI to one or both cameras with not much success. I also had the problem that if I setup a canvas and assign it to world space, it is not visible in the cameras anymore.

Any tips on how to solve this issue would be very appreciated!

 

Ok, figured out the last point, I just have to add the UI layer to the camera's culling mask.