I think it will be nice to have such a special page sub-set. Wikis reusing content from other wikis (e.g. Wikimedia or other projects) utilizing this extension would benefit for knowing if a module is missing, etc. post importation/creation to get the show running.
Currently we have a long standing, simple-to-follow & logic based [[https://en.wikipedia.org/wiki/Special:SpecialPages#Maintenance_reports | maintenance group of generated listings]]. This group has a sub-set of complimentary Special: pages within it detailing specific maintenance deficiencies per a set group of namespaces. This sub-set is illustrated in the table below...
| Uncategorized //categories// | Unused //categories// | Wanted //categories//
| Uncategorized //files// | Unused //files// | Wanted //files//
| Uncategorized //pages// | Unused //pages// | Wanted //pages//
| Uncategorized //templates// | Unused //templates// | Wanted //templates//
.
In short, this proposal requests building upon the existing "foundation" of maintenance Special: pages illustrated in the above table by adding the following equivalent for the Module namespace to it ...
| Uncategorized //modules// | Unused //modules// | Wanted //modules//
.
The caveat in adding such a sub-set would seem to result in a rather "large" maintenance group section in the end.
If so, further discussion of any possibility in filtering each specific maintenance task by namespace(s) to shorten the list is needed (iow- not sure filtering of such Special: cached pages is even possible never mind feasible).