I wouldn't tie a knot in the pendant, but you may want to check your line lengths (sorry, I don't have the measurements). I would play with the length of the up-line to adjust CB limit. On the DS II the CB is lifted by a short length of SS cable and the CB is limited in how far it can drop by the lengh of that cable. Seems to me the WIDGEON setup must have a similar limit. Below is the Diagram that I got from Rudy at D&R to put in my Widgeon Manual and the diagram of the DS II for reference.
My old Widgeon was a 1969 model and so had the lever-operated CB, still... I think it might have been able to drop to a position slightly beyond straight down? I've never checked my DS II for this, but the cable does seem to prevent it going too far.