Drew Adams wrote:
> Presumably the final wording will make clear that, per the doc
> string, this mode is only about "replacing [classic quoting]
> with [curly-quoting] _as you type_".

Thanks, done in master with the attached patch.

> (This should not be only under a `substitute-command-keys' entry.)

Also done with the attached patch.

> that option has no effect on the quotation style used in the manuals.

Correct.  Display of info files is unaffected by the changes in Emacs master 
over the past month or two.  Info files use curved quotes as of Emacs 24.5, due 
to a 2013 change in Texinfo, not in Emacs.