Seems overly complex. Why not just use a material? I'm not a big bryce user (deciding after a few hours it was just too different and life was too short) so maybe I'm missing something obvious here. As an aside, you can actually make completely imobile joints and add other such limitations by editing the cr2. This does add about 450 lines and 8.5 kB to the CR2 (per joint), but you can do some fairly cool tricks with it.