I get a lot of emails from Maniphest (and other apps), only some of which are relevant. I've spent a decent amount of time trying to tune my email preferences to my liking with mild success. Something that would be very useful is the ability to distinguish if someone explicitly tagged me vs. if they just commented on a task I'm somehow attached to. If someone explicitly calls me out either in the description or a comment, I'd like that to be "louder" than other notifications.

This is partially doable via Herald rules, but you can currently only set rules for the description contents, not comments.

I think there are a few different ways this could be accomplished:

1. Add a "someone mentions me" option to the myriad of email preferences that already exist. Adding more dropdowns to that page doesn't make me excited, per se, but it would at least enable the granularity I'm looking for. I view this as adding more dials to the email firehose (yay analogies).
2. Don't add an option, but change the subject prefix based on whether I am mentioned or not. For example [Maniphest][Commented On] T1234... would become [Maniphest][Mentioned You] T1234.... Then I could get the granularity I want by way of email filters. This keeps the firehose, but makes it easier to manage downstream. One potential downside here is it could potentially break any existing email filtering people have set up, but that might not be avoidable anyway.
3. Add a Herald trigger based on comment contents. I could then slowly abandon other notification types and gradually move entirely to Herald rules for specific things I want. In analogy-land this would be shutting of the firehose and choosing squirt guns individually.

I don't have a strong preference for any of these three, but I'm leaning towards the first one just because it requires the least amount of user-education (meaning I don't have to tell people to set up Herald rules or email filters to accomplish it).