Hello knot4u,
interesting idea.
I just tied a sling, two pieces of rope, the EDK on one end and the Ashley stopper as a bend on the other. I gave them the heave ho approximating two bends in stress.
What I found in this puny test is that the Ashley stopper bend was trying to "suck" the bights that go over the working parts down into the knot.
The rope I used is a static rope of 11mm with a fairly coarse sheath. Was a bear to cinch up, but it got there after a few yank and pulls.
Tried again with my infamous-fail-all-knots Titan 5.5mm and got the same result.
Double tucking the working end helps it somewhat, but adds more bulk than I would like and that could become a unneeded climber's challenge.
I don't think I will try it in the real the next time I go climbing. Well, I might try it close to the ground. ;-)
SS