El moves about pretty well. He is an HMPKEE, which is what I like about him. Not super long EE trait, just enough to give him a butterfly kind of look. He hasn't shown a single problem for swimming or even buoyancy.
And yes, I do intend to breed him. No super EE, and probably to a plakat female to keep the short finnage. I've watched my fish swim... They use their dorsal, their anal, their caudal, their pectorals - every fin they have is used much like a plane adjusting for wind, height, turning, etc.
Do I intend to breed only for the look? That'd be stupid. And immature. Yes the look will be there to breed with but without a healthy and strong fish... You have nothing. Understandably there will be tail types all, some, or most of you hate and will go off ranting about. Just stop. Don't like it, don't breed them, don't support breeding them. Did you know most people respond to gentle encouragement and not a kick in the ass?
We as breeders have choices. Breed for looks? Breed for health? Or even bring back health with the looks. Doubletail, rosetails, EE... All technically deformities. But we have a choice. Send them back to the depths or strengthen their genetics - since we decided to take on the role of Mother Nature and god, we now must pay for our decisions and tend to them reasonably.
That's my input.