I've just been playing with the new DeoVR app on a Q3 and previously noticed that the 'Sharpness' option is actually really bad (not being mean) for adjusting the sharpness / detail of the image.
However, i noticed it alters what i would describe as 'The Gain' and started playing with it on Alpha Passthrough scenes and found it a great tool for blending the image with my surroundings, i tried it in a dimly lit room and turned it down to try and match the rooms lighting and got some pretty good results as it really helps with the lighting on the skin as it sort of creates shadow, obviously it takes a bit of tweaking to get the right results and also varies from scene to scene.
It's also a good tool for scenes that have poor white balance with over exposed skin losing details as it tones it down especially in conjunction with the 'Brightness' tool
Trust me, i talk a lot nonsense on here but this is pretty good and worth playing with as i've had some very good results.
Advice to the ongoing development team of the new DeoVR app ; -
Personally i would keep this tool but rename it to 'Gain', 'Blending' or 'Ambience' and have another attempt at a sharpness tool.