Maybe a collapsible 50mm f2 that focuses to down to .7m.
AFAIK there are no collapsible 50mm lenses that gets closer than 1m.
When focusing this close, it's also important that design doesn't focus shift, which unfortunately a lot of CV lenses do..
Maybe some kind of modern triplet design, like for my 4x5 I have a 210mm Rodenstock Geronon, those are great for portraits!
Don't trust anything I say or write before I get my morning coffee, at least I don't.