the oblique portion of the collar's rope...that tends to be a little too free to move.
That is why I had buried it there, in between the rims of the two nipping loops... ( At the knot you show, you can also pass it "under" the two "blue" oblique elements.) However, when the knot is tightened, I believe this "motion" is restricted, and it does not present a problem any more.
Tie both knots, the one you show here and the other shown at (1), test them, and tell us which one you prefer. With the "8" shaped collar structure, which is not as tight as the Strangle, my concern is that, under heavy loading, the lower nipping loop will drag the tail, and "walk" away from the higher one. I prefer a knot that will remain as compact as possible.
1.
http://igkt.net/sm/index.php?topic=4308.msg26877#msg26877