How does this hold a knot?
If you mean Amsteel, it doesn't, not very well. Dyneema in general doesn't. That's why people generally splice it instead, meaning it's hollow, and you feed it through itself. When you put weight on it, it tightens up like a finger trap and the friction holds it in place. Again, you really need to read the suspension stickies on hammockforums.net. Start here
ETA: Or if you're averse to the learning curve or the work building your own suspension, you can get pre-made suspension here