Why does he say it doesn't work? Because it doesn't work!

Why doesn't it work? Because the programmers didn't make it work.

Why didn't they make it work? Ask Microsoft; if they answer, let us
know.

Purely as a guess, it doesn't work because hyperlinked TOCs link to
bookmarks that get written around each heading. If the RD TOC entries
were going to work, Word would have to open every RD'ed file for
writing, not just for reading, and write bookmarks into that file. Or
it would have to check every entry for an existing bookmark of the
correct type. Both options sound inconvenient. Also, when the user
tried to use one of the TOC entry bookmarks, Word would have to open
extra files to be able to jump to the entry. The user would get
confused about what document he was in.

Bob S