i use single.
That is:
Blake's at 1x 6000#(or whatever you use) test leg(s) of line to support
vs.
Icicle at 2x 3761# test legs of line to support same load.
If, both lines are same stiffness, the smaller diameter will have less leveraged loss around the tight bight of a krab; per same load. Leveraged loss on tight bight is resistance to bend (stiffness) X Height at arc/bend of the bent axis (diameter in round, or as flat as it lays in 'flat'). A flexible lay by Tenex X nearly flat/ dimensionless on arc of bend give very little leveraged loss compared to others i think.
edit: i think if the Bitters comes around a Turn and bends the Standing; the Bitter Bight leverages against the tensile potential of the line. Also at this same point the krab friction starts. So we have a sudden high tension area and a sudden stop in line stretch.
But in the case of the Double/Triple anchor to self to form eye called a Scaffold; the subsequnent Turns tend to reenforce rather than destabilize this critical area. By A)making the same bend in line over a longer distance (thus a 'softer' bend) and B) givng a graduated decrease in line stretch, as the turns gradually grip the Standing with greater and greater tension.
Thus the 2 suddenly impacting changes are not so sudden and impacting/ destabilizing the system to premature failure. These things test out very well, even with a measured amount of slip/seating to give better dynamic absorption. i use 4 turns on my lifeline termination (
for a cinching up type termination) for built-in (light duty) throwing weight, so that it looks like a Blake's that the tail stays under all 4 Turns, not exiting after 2.
Or something like that....
