I don’t have a ready setup to answer with, as configuring a scene capture depends on the circumstances and your needs (did not ever cross my mind the mirrors would be that large and on peripheral monitors!).
Do explore this panel to start with, the flags control what is captured:
I know that Deferred Lighting is a hog. Never seen a summary of details regarding tangible performance benefits. But, as a rule of thumb, I’d start with everything off and hopefully arrive at the visuals that do not compromise on the visual fidelity too much.