Knots are fine. Muddy lifeline plenty heavy strong but I recall it is pretty stiff. Ditto on making sure equipment is sized to rope.
A good deal on a tether is the Kook brand. A bit overkill in size but ready to go as is or add Ropeman for easier adjustment.
Here I am using it with different hardware.
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Amazon.com : ZOOK Adjustable Lineman's Rope 1.0 | Hunting Safety Line | Trees Stand Harness Rope | Treestrap | Climbing : Sports & Outdoors
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