I believe that the single "toggle" mechanism, by the slipped Tail End perpendicularly to the axis of loading, is adequately secure - you do not need to repeat it for a second time, because, that way, your loop is released in two stages, not one ! It is not an "exploding" loop any more.
Are you not satisfied with the loop you had presented some time ago ? ( and which is also somewhere in the ABoK, if I am not mistaken - but I can not search for it right now )( See the attached picture ).