Hello, I am curious about needing to be able to block - if you are tired of a specific discussion and no longer wish to participate in it, did you know you can stop being notified of further posts?
Here is how to do it:
At the beginning of each discussion, right next to the 3 dots, is a bell.
Click on the bell, and choose "Mute this discussion" Then click "Save"
You will no longer receive notification, either via email or in the App, about that specific discussion.

I occasionally do this on discussions where I responded once, a long time ago, and have no interest in seeing the ongoing discussion.
Will this satisfy your need?