clarkwinkelmann Here's the thing, and probably the main reason why I'm trying to get this into core.
It's not like I'm shifting work to you - you already have a similar system in place (which counters duplicate notifications for a post). However, correct me if I'm wrong, but looking at the code, while there is something similar going on, it's not something that you can reuse. There is also the issue you talked about about having different notification types that you might not want to mark like that - creating an extension doesn't actually solve the problem, it just shifts the process of solving it onto someone else.
I'm not saying you should just dirty your hands. I'm saying that if you yourself said that one of the reasons this should not go into core is because things might change on your part, then perhaps a part of your job would be to provide an extension API that doesn't just create work if you change something. In other words, it would be cool if there was a Flarum-defined comparator for notifications based on content, or at least the will to let someone PR it. This would then not only be used for this discussion's title, but also for choosing which extension's notifications you want to receive, up to which level, it could enable you to choose which notifications go to your email and many other things.
