Why would you ever manipulate a texture outside of the engine? Is that what you are suggesting? You should never have to correct them outside of your engine, my understanding is that you have to tell the engine to correct them because VRay is using 1.0 Gamma.

I just read this tutorial and it is all starting to make more sense to me.

http://www.aversis.be/tutorials/vray/vray-20-gamma-linear-workflow_01-old.htm

Based on what is being said here, my guess would be that you should NOT tick those on as long as you have Input Gamma set to 2.2. Although maybe you need to tick them on for Correct RGB? I guess it might be worth a couple of test renders with it on and with it off. If you test it, post your results.

I just have never understood it. All I know is that if I export to EXR and use Linear mapping with clamping turned off, I can get what I need from Photoshop as far as correcting lighting goes.