I figured out my unraveling mistakes. The successful ones were likely the ones I forgot to do, roughly 1 in 5 I'm guessing. A pretty bad fails rate (80% or so). The more careful I was, the worse it seemed to get. I realized my mistakes today and ET VOILA! 100% successful. I'm almost too proud to admit it... but HEY! If I make a mistake someone else may one day. Here it is:
My Syren version 2 did not have arrow(s) pointing which way to twist. For some reason, I put in my head that I had to reverse drilling orientation (flip the reverse switch on the drill) when going from one stock to the other. Big mistakes... I basically keep adding tension to the rope without releasing it. If I was not careful when cutting the rope at one end, it would twist on itself aggressively.
Then I read one of Chuck's comments on rope making: that when you carefully balance the tension from the first and second twist, the rope would just lay flat (without much curling, unwinding) when you cut it from the stock post. That was the clue.
Corrected the mistake and BANG, released one end and the rope just lay there. Did 5 other ropes of different sizes, and YES!!! each almost seen better than the previous. A nice sight.