We've got a nice list of unused extensions in our repository that don't stay updated, and are cluttering the directory. Many of these things stemmed from projects that I'd class as "nice to have, but not essential" and are a lot of hassle to set up. A shoutout goes to Configure, FlaggedRevs, and CodeReview.
Which wiki does configure work with? ShoutWiki Hub only? I'm surprised that it even works at all in its curernt state, given the fact that the documentation page says it's incompatible with MediaWiki 1.28
Sorry, I should have phrased that a little better.
Configure works okay for single wiki installations, not wiki farms with 8800+ sites.
And yes, things like version incompatibilities are also a reason some extensions are on my list of things to remove.