The yoyo line is credited to Dave Morley, a Scratch Bunny, and is original fitment on the Fury range of kites. It's an easy add-on to any kite and you can have more than one for multiple wraps. You can use it on its own or as a security measure in addition to stoppers.
easy to fit
no need to modify LE
one wrap per rung
can snag and be a pig to unwrap
not as connected in flight when wrapped up
Here's a Cosmic TC retrofitted with two lines.