It is really rare for me to "need" more exposure than box speed.
f/11 vs f/16 is not about deviating from box speed. Just take a known good meter and measure in reflected light a number of sunlit scenes. Especially, but not only, landscapes with foliage.
Simple for me, the OP said so.
Then he knows what he's doing, and no need to show us a digital version of his pictures. You gave better advice in your post #5 of this thread.