[Inkscape-devel] Save As option?

I missed the discussion of this new option but, honestly, I don't understand it from the tooltip and the Release Notes (which I edited some, but still).

What is "current working directory"? For an average Windows user this does not make much sense I guess. They just click icons. Can you explain it in more functional terms?

The tooltip explains what happens for previously saved or not saved documents. But both these are for this checkbox on, right? What if it is off?