While I'm sure it would be helpful, I'm suspicious of the accuracy of that method; my run of perldiver.cgi (version 2.32), on my DH server, reported 2369 modules found, and that is a lot more than the wiki reports.
Granted, this includes many "sub-modules", but even a truncated list would be a very long page, or series of pages. The fact that perldiver does not report version numbers for all of these modules, and the fact that different servers can easily have different modules (or even different versions, depending upon when the server was placed into servce) would make such a list impractical for use as a general reference.
DH is very good about adding a module, upon request, for a user with a particular need (if they can ascertain that it would not be harmful to the server's stability to do so) which further complicates the publishing of an authoritative list that would be true for whatever server upon which a new user might be placed.
Really, for accurate information, each server would need to be cataloged and you would have to know which server you are investigating.
The perldiver.cgi method allows each user to check their own server, but I'm afraid a support contact, or a query such as the one you made here, is probably a better way to determine what is available for "window shoppers" or other pre-sales queries.
I feel pretty confident that the version I reported to you for the GD module is "safe", as I have been on the same server for 8 years now - newer servers are not likely to have an older version of that module (and may very well have a newer one! .
Additionally, for prospective customers, the most important point, IMHO, is that with the shell access DH provides, you can always install your own perl modules - which makes what DH has already installed "by default" much less critical.