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  > > That kind of hook is pandora's box.  It is too powerful, and would
  > > interact in complex ways.  There will be many cases that are hard to
  > > implement correctly, or cause trouble.  To implement this probably
  > > means future hassles for ourselves and for package developers.

  > I actually implemented it, and it worked as intended.

I think you mean it works as intended in your use case.  I am talking
about something else.

My experience says that this kind of feature is likely to fail in
various peculiar cases, which would make it a maintenance burder.
Also, it is likely to show show strange confusing behavior which would
lead to trouble in debugging.  We are better off without it.

The other approach has the virtue of being entirely internal.  It will
not require an announcement, or adding to the Lisp manual.