I’m of mixed opinions on this. With the Mozilla use-case that would be the best place to put it - burying it away in a user’s preferences completely disassociates it from the category and makes the feature near impossible to discover - but for every user welcoming it I imagine there would be many more finding the new menu horrifically confusing.
I don’t think it’s possible to square this circle and make a UI which is understandable for both the classical-Discourse/forum use-case and the Mozilla/mailman-esque use-case for anyone other than people like us deeply involved in the project.
@erlend_sh I still think your post from last summer about this is brilliant, and I regret I haven’t had the time to throw any development resources behind making it a reality:
I wonder if this per-category email-only notification setting we’re discussing should exist like “Enable Watching First Post” in your proposal. That way we could set sane defaults on an instance level (not show it on Meta Discourse, definitely show it on Mozilla Discourse, for example) but still allow power users do whatever they want on any instance.
EDIT: In the meantime, I would agree with @sam on the placement of UI. I don’t think adding this feature should depend on the whole-scale revamp of the behind-the-scenes notification settings. Indeed, that should probably be done separately from this - being able to additionally hide the category-level tracking option by default would be very useful on Mozilla Discourse considering how useless the option is there.