Safety blue is pretty soft if I recall correctly, try stable braid 1/2” or one of the firmer 16 strand linesYou did a limb that heavy by yourself??? Now I know I've been missing the boat. When self lowering with my new Morgan Block I have been using an extremely fuzzed up piece of half inch safety blue. It wasn't giving me near the right amount of friction and I plan to bring new rope for it the next time.
Additionally if anyone notices a particular rope that jumps up in friction I would be interested to know type.
Yes chislebit I just girth hitched it on. The Ultra sling I bought has pockets that are just a tad snug to thread the MB through but I like it in spite of that,