Hi yChan,
I have the quick test on your Mocha loop, for 1/4" rope after loading can be untie, no easy but not too hard either.
well secure and retain compact form.
For 7/16 rope, very hard to dress the knot, after loading 1200kg, very easy to loosen the outer collar, take me 3 minutes
to loosen the inner collar, and then rest is easy. The inner collar doesn't jam, it snug tie, just no room to maneuver it.
Something wrong with my new jack, I have to return it and get another one, That's all I can do for you.
謝謝 alanleeknots