Although you say this is fairly common, I haven't heard of anyone using or requesting this type of feature. Do you have any real-world use cases for this? Before we start adding more read methods I think we should know who wants them and why.

I'm not sure duplicates should raise exceptions. To me, the current behavior of using the last read section/option is fine. It's predictable and it works. Halting a program's operation due to duplicate sections/options seems a bit harsh to me.