About [[Extension localisation statistics]]
Fragment of a discussion from Support/LiquidThreads
If you have time you can submit a patch yourself, they are the scripts stats-* in https://git.wikimedia.org/tree/translatewiki.git/HEAD/bin and you can find docs on groupStatistics.php in the Translate code.
Thanks. I have submitted gerrit:79469, but I don't know whether "ext-di-di" should be "ext-di-gc" or not.