Example for Abusefilter: https://wikimedia.biterg.io/app/kibana#/dashboard/95487340-6762-11e9-a198-67126215b112?_a=(query:(language:lucene,query:'repository:%22mediawiki/extensions/AbuseFilter%22'))
Not sure how to do this without lots of manual work though.
Changing repository name in the link should be enough. A simple script should be able to add new column to the table with that data. I didn't test it yet, but it should not be a lot of work. If that's something that would be useful, I can give it a try. I can generate a test page, copying Developers/Maintainers and adding activity data to it. Let me know.
@ZFilipin (WMF) Thanks for the reply! Not sure if it's worth to display a number directIy in a table (one click less but hard to find one criterion which is meaningful enough), and I think that improving Template:MaintainerLinksExtension makes more sense than adding another column - that template already has a "Contributors" item which is quite related to what I'm proposing ("Last code review activity" or something like that)?