While 3D Widget rendering in VR (when parented directly to the camera) is broken, I draw global menu activation progress bar and crosshair in the HUD:
That worked perfectly fine in 4.11.2 and both crosshair and progress bar were drawn dead in the center of the screen in Gear VR. However, in 4.12.4 same BP draws stuff off-centered in VR, but centered in PIE.
Here is VR capture: https://youtu.be/7hmKAtvAKpo?t=1m29s
Sounds like a bug. Please let me know if it is and I will file it over at AnswerHub.