chad556
ArboristSite Operative
Here is how I tie in. I use the anchor hitch for line termination with an XT friction hitch and micropulley for my split tail. I like the anchor hitch because it unties easily and it doesnt force the rope to bend in a very tight radius at all compared to other termination knots. I also like the fact that the tail sticks out sideways instead of straight up. Its personal preference but i feel like it has less of a chance of interfering with my hitch if the tail is shooting out to the side(though in 046's method the tail is whipped and wouldnt get in the way at all anyways). And like any termination knot when tied, dressed and set correctly there is absolutely no way for them to roll out. I usually only have about 2-4" of tail coming out of the anchor hitch BTW forgive the picture it was the best one I had.
As for tying in a system that has only one carabiner on the saddle, I have tried and failed at that many times. One sure option would be to get a hitch climber pulley, never used one but its on my wishlist for the same reasons you mentioned. Maybe if you somehow tethered your two carabiners together you would eliminate the ability of your split tail carabiner to slide around as much, thereby leading to better performance. There are literally thousands of options to tie in the way your thinking so don't be afraid to experiment and have fun. Once you come up with something that works post a picture of it here if your not sure about it and we'll help you out.