not sure if this would help or hinder, but I have a freebie text filter that can be applied to a clip rather than a generator that is applied to a sequence
its possible it may be useful to you as you're trying to associate the titles to clips rather than timelines. you can grab it from
http://web.mac.com/andymees
possible workflow would be as above except director downloads clips, opens in FCP and adds subs as needed, then saves, zips and sends you his project file. you then open the project and reconnect.
when the cut is locked you can prep final subs using whatever tools / plugs /method that you see fit
