Hi', Matt.
I've been using plastic coated lines since 1960, and I haven't found a way of making a connection that hasn't resulted in the plastic coating cracking where it meets a 'step' in the line. I've tried nail knots, needle knots, whipped loops like yours, a slightly different whipped loop, braided leader loops, plastic cast connectors and the old-fashioned overhand knot at the end on the fly line, and loop the leader to it using a clench knot. I have even applied Vy-Coat plastic varnish to smooth out and taper the joins --- they all crack the plastic coating.
One day, someone might find a way of putting a reverse taper on the butt of a heavy tapered cast, say an inch or two in length, so that it may be inserted up into the core of a fly line and glued in place. Preferably, the thickest part of the butt will match the diameter of the fly line, and the leader and fly line will have matching stiffness. Whoever achieves that will make a perfect continuous tapered line/leader -- and a fortune.


TerryC