And could we have some way to avoid mass notifications when we are mentioned in a newsletter like The Signpost, This Week in GLAM, or the Wikidata Weekly Summary, which are posted to many talk pages?
I'm starting a thread here, for easier discussion. and note-taking.
There is the blacklist functionality (docs at Extension:Echo#Usage), which could potentially be used to blacklist User:MediaWiki message delivery. However, I believe this would also suppress the "your user talk page was edited" notification, which is (probably?) not desired - although it would still trigger the yellow talkpage indicator (OBOD replacement) so perhaps that is sufficient?
I'll ask the devs what our other technical options might be.