Note that the actual geometries (meshes) are moved by using [Orient] after the simulation.
During the simulation or “inside kangaroo” (goals etc) you should want to use simplest possible geometries, like points and lines.
Here i made a rectangle exactly in the “soul” center of the chain element thickness.
Then from that rectangle i made its points (corners conceptually, but also more for some bonus quality) collide with an offset-ed mesh of your neck-stand, so the computation is simple, just point to a mesh!
Similar, with the [Collider] i made the rectangles collide each-other, but again those are simple lines geometries. (Big thanks for the collider component anyway!)
Lastly, at the kangaroo output, you pick just the oriented frames and relocate an actual mesh.
The result is not completely correct because the collisions behave like the geometries are circle/pipes/spheres (just distance-based) … but the whole process is much faster than a true solid body collision.
If you would use another software (like blender?) this amount of solid mesh collisions wouldn’t be a problem at all… but it’s difficult to leave the rhino environment (i’m just lazy to try it…)