This was closed as fixed in 29.1.  I don't have
that release, so I can't check this.

I hope this problem is fixed.  I was wrong about
the solution being to just fill.  That would be
catastrophic for some variable values, such as
for `directory-listing-before-filename-regexp',
where SPC chars are significant etc.  (For that
var the result of filling ended up, in effect,
replacing the SPC before the + at the end of the
regexp with just a newline.)

Some enhancement of pretty-printing, to control
(or at least to try to control) the width is
needed.  Maybe that's what's been implemented as
part of the fix.  If so, great.

The problem, in general, is this:

* We need to be able to print (e.g. pretty-print)
  any Lisp value.

* Buffer `*Help*' should not have lines longer
  than what the style convention calls for.

Trying to finesse those two different rules is
the difficulty.  If you've come up with a good
solution, bravo.