Currently installed only in testwiki (since 2017); funding for this has stopped and the work hasn't significantly moved since then. The code base is subject to the same slow bitrot as all code, but without any active owner this is becoming more problematic. See for example T239674 T246757 T254005.
I'd love for a team to take it on, finish the work, and deploy it more widely, but that seems unlikely right now (and re-deploying isn't too hard if that does happen).
[CC'ed maintainers per https://www.mediawiki.org/wiki/Developers/Maintainers.]