Toggle effects on/off in Single pass render expensive

I crossed posted this in the Image effects section, please remove the one you think least fits.

Hi, we notice huge spikes on VR.WaitForGPU when enabling and disabling effects like Vignette, Color correction and greyscale when Single pass render is being used. If I turn off Single pass render all is fine



We toggle all 3 effects on and off, Color correction indicates damage taken, greyscale death and Vignette we use to reduce FOV when moving for people that are known to get VR sickness

 

hey, this thread might be helpful. Not sure. http://forum.unity3d.com/threads/supporting-single-pass-stereo-rendering-in-image-effects.419850/