I just played with the Role and Person documents a little bit and, hooray, the repopulation isn't really an issue. This is because:
a) the formatter seems to be handling the repopulate correctly, and
b) there's actually only two times this needs to repopulate - on return from a lookup and on open from save. The qualifiers cannot be edited other than begin and end date once the document is submitted. Both of these cases work.
That simplifies things a lot. I'll start working on the "Y"/"N" fix solution.