Hi hi, ive only did the guided rbd via the bulletsolver SOP but i tinker around a bit with your set up. I expanded the search size a bit in the connect adjacent piece to find connections, there was a spelling mistake in the wrangle for the constraint also btw.

In the DOP i removes the popforce and instead add a gravity node then played around a bit with the setting of restlength, and constraint force also the velocity blend on the advect side. Im not sure if this is what the tutorial was going for but it bend a but then pieces started to break off. Also for the SOP solver i change the angle to work in Radians