I have recently figured how to work this thing, but I'm asking anyone that knows (if there even is anyone) how it works intirely how much damage does the joint need to take for it to dismember?

That's the DMT. What I'm talking about is completely different.

Recently hampa added a function to the game that allows you to see the damage a joint took during a hit by typing /dm 1 and hovering the cursor over said joint (kinda faulty, but it's a new feature).

There aren't really many people who know about it and I doubt there's anyone who uses it, that's why I didn't have high hopes for an answer.

It always seemed like a broken feature to me, but when I get home later today I'm going to check it out in 4.41 and do some testing to see what I can figure out about it.