The import script has a number of problems that I'm going to have to hack before importing my board.
Regarding using public display names instead of login names, I haven't worked out all the details yet, but ...
The import script loads a member profile into the array $member. $member[0] is the login name, and $member[15] is the public display name. So replacing $member[0] by $member[15] in the appropriate places should do the trick. If $member[15] is blank (no public display name), then $member[0] should be used.
