I have two levels of categories in my forum. I would like to allow users to change their notification settings on the top-level category with an option to apply this setting to the sub-categories within the parent. This prevents them from needing to react to category changes by once again updating their sub-category settings.
I’m thinking something like a checkbox to enable the notification selection to apply to all sub-categories.
a main section may have dozens of sub-sections, it’s annoying to mute them all manually.
I think a modal would be better. That way when you change your tracking status, we say something like:
Would you like to apply this change to *all* underlying sub-categories?
You're currently Watching 2 sub-categories, and Tracking 1 sub-category.
This is what makes it a not-so trivial change though. A convenience feature like this one needs to communicate very clearly what it does, so that users don’t shoot themselves in the foot. No one wants to make a mistake in bulk 
If a clear UX path is laid out, we’d probably be open to a PR on this one.
Has anything happened in this area? My categories are still a bit in flux, and they might continue to shift. I would like someone to be able to set a notification for a main category, and have it apply to all sub-categories, even if new sub-categories get created later.
To me, conceptually, a topic that is in the “Main - Sub” category is also in the “Main” category. I expected that watching “Main” would notify me if someone created a topic in “Main - Sub”.
Même constat de mon côté. Au cours des derniers mois, nous avons progressivement créé de nombreuses sous-catégories, mais nous venons seulement de réaliser qu’il faut notifier tout le monde pour qu’il aille manuellement régler ses abonnements à ces sous-catégories.
Pour moi, la solution la plus évidente consiste à répliquer le paramètre d’abonnement pour tous les utilisateurs d’une catégorie de premier niveau vers chaque nouvelle sous-catégorie créée. Cela pourrait entraîner un léger surabonnement, mais il est facile pour chaque utilisateur de corriger cela via les liens contenus dans les e-mails.
Par ailleurs, Discourse est tout simplement fantastique.