It all depends. If you're producing a Pro version with extensive language support and extensive features, then adding those characters makes sense; for everyday display work, it really doesn’t make much sense.
In the process of designing a typeface, I'm wondering if it's worth the effort to design glyphs for currencies that are not in use anymore, like pesetas and francs. I realize the symbols might still be in use for historical reasons, but in a display face, I think it's rather unlikely.
How do you guys do? What do you think?