My best ultralight line is Berkley 8# Hi-Vis Nanofil. A 6 foot long 6 pound flourocarbon leader is always added using an Alberto Knot.

IMO, the Nanofil can get a bunch of line twist and still cast without problems. It cast further than anything I know of. Close inspection of my Nanofil with show that the line has many twist. From time to time the leader is removed and the line is drug behind the boat while moving slowly to remove twist.

Btw - all of my fishing is cast and retrieve or casting a float and jig.