I could call this soft shackle variation #4. What I was trying to do here was create a way to attach the jib sheet eye splices to the soft shackle without using a ring hitch which might constrict the sheets too much. The diamond knot in the center is of the three strand variety. I have tested this to between 2000 and 3000 pounds using 5/32 Amsteel and the knot does not slip so I would expect it to be similar in strength to other variations without the constricting action on the sheets. (My test setup cannot put more force that that right now). The diamond knot is not easy to tie so I put instructions on my web site.
As a variation, adding a stopper loop to the shackle creates a double ended soft shackle shown here in the closed position.
Here is the write up complete with instruction on the knot.
Soft Shackle Variation #4 - Double Soft Shackle
But truth be told, I am favoring the version with the ring hitch as it is simpler to use and I don't think the constriction will be a problem in the real world.
It is written up here:
Soft Shackle Variation #3 - Ring Hitch Soft Shackle
Allen