@bob_ no dice! That’s a flaw. So apparently, you have to stick with a question and click on it, anytime anybody says anything on that question, to know if you’ve gotten a response.
In the same vein as @petethepothead says, why bother unfollowing a question? Once in a while, an “old” question will reactivate. So, I only unfollow questions that I really truly have no interest in.
Fluther has a contact button at the very top. The easiest way to request new features is to use that link to send a direct email to Andrew and Ben. It could be something they are working on, or, they may be focusing on other areas. Nevertheless, if they are interested, they’ll put it on their to-do-list.
The code behind the @username feature is far less involved than it would need to be if the intent was to send users every comment in which their name was mentioned.