I've now edit quite a few tracklists in NGS and in 100% of those cases I just wanted to correct typos or change the language, never change the times or the recordings. In this situation it would be extremely helpful if one could lock the recording associations so that no matter how much you change you don't have to manually match the result up with the old tracklist. Perhaps this could even be a default, with a big fat warning requiring you to explicitly say "I mean it" if it looks like you're changing the order of tracks or other rewriting too much.