People get screwed up on a crown knot .The easiest thing is to rememeber once it's tied all strands will be facing back towards the line .
Generally speaking you don't put a back splice on three strand nylon .You're probabley as well to use a piece of shrink wrap instead .
I suppose you could short splice 3 strand but the only thing I've ever seen or done would be eye splices .A long splice would be out of the question I should think because of the soft lay of the rope .
From my perspective on bull ropes and the like you're probabley as well off to eye spice both ends and be done with it .If you screw up one eye you've got another to work with .Later cut the bad eye off and do another .
Long time ago I spliced all the mooring lines on one of the subs which at that time was 2" nylon .4 main lines ,eyes both ends and 4 spares .The lines were 300 feet long .Now of days they use braided line instead of 3 strand .