Gear VR GPU issue in Unity 5.4

With Unity 5.3 I'd make the OVRPlugin calls cpuLevel and gpuLevel, setting them to zero so the Gear VR video app can run indefinitely. Performance and frame rate was fine (on a Note 4 test device). But with Unity 5.4 this setting results in nasty judder. I have to set gpuLevel to at least 2. This setting has previously resulted in overheating. Is there a change in Unity 5.4 that results in sucking up more GPU? Reverting to 5.3 allows zero settings and thus long playing sessions.

Any info on...

Gear VR GPU issue in Unity 5.4