Comments and notifications

In standard Elgg (3.0) it's not possible to reply to comments. And, if you just post a comment on a comment, a notification will not be sent.

I've checked Ismayil's plugin hypeInteractions, but it requires 3 other plugins to work and one of them throws an error (hypeStash). And, they also have many other features that I'm not interested in. I only need the notification part.

Anyone know of a plugin?