Thank you for your reply.

Sadly the SiteDocClan didn't have enough foresight to declare in advance that cpan:// links to whatever interface is best to read CPAN, and doc:// links to whatever interface is best to read perldoc. Maybe you're right and this is too late to change now. Next time we add a new shortcut, we should declare this kind of freedom. Afterall, if you want links on a particular website, you could use a direct url.

Update: let me note that my patch would also add new shortcuts to explicitly link to search.cpan.org, namely searchcpan:// searchdist:// searchmod://. I volunteer to document these changes to What shortcuts can I use for linking to other information? and How do I link to modules on CPAN? if the patch is applied.