I have this question........... it's exist somethigs similar ?
Somethigs can be TEST, in some mode, if a repository installed it's online ?
Now when a repo goes offline and it's not more reachable you can found some info on kodi.log during the daily check update of addons.
But usually the name of addons it's referred to a totally different named site and watch the kodi.log can result a lot of confusion.
Directly from KODI.......... if a repository it's offline apparently you can ACCESS equal to content (probably you stay to watch somethigs like a cache) and nothigs it's reported on screen.
If addons requested it's exist......................... i thinks it's a good idea.