Well, I intend to do some still life, product shots etc. Initially with two light sources or one and a bounce surface. I thank you for your answer but my question was not about the "look" of it (whether 2:1 is good or not, how to judge visually etc.) but about the difference in results between method C and method B, it really was about metering technique so to speak.

Is there any application that requires method B, or, instead, can I just ignore the existence of the flat thingy?

Fabrizio