The thread is not "stronger than a knot". The thread is only keeping the rope bound tight together. It is not necessarily taking the force being applied to the end of the rope. It is creating friction between the two sections of rope. It's important to understand that you're not "hanging by a thread". You're hanging by the rope, which is bound against itself, just like in a knot, or in a splice. All of which can be done improperly and kill you.
Not sure if you're coming from hunting on the ground, or in a stand. But If it's a stand, I think you need your strength expectations calibrated...
Take your oplux, and put a knot, or a sewn eye(by a certified supplier) - make ten setups. Pull on them until they break. They're going to break at somewhere north of 3000lbs of force(I'm being conservative)....every. single. time.
Take your climber, or hang on, or whatever stand you were using. Pull on the platform with 3000lbs of force and see what happens.
Should your stand ever see that much force? No, of course not. But neither should your rope. If you introduce that much force on a static tether attached to your body, you will either not live to tell us about it, or you'll be telling it from a wheelchair.
The strength of a tether built by a qualified supplier should be the last concern you have in this game. There are many other significant risks you're overlooking...