I am quite convinced of the outcomes because of the real experience.
  Hope we shall not make such kind of mistake with Coda.

I was rambling without a lot of AFS/DFS experience.   Given that
others have tried the approach I mentioned, and that it is awkward,
it's best to ignore my coments.   I don't have spare time to do this
anyway, and there are far more pressing things in coda to fix.