Attaching a physics constraint to a mesh socket

My situation

I have a frame I want to hang in the air with a cable passing through an eyebolt on the top.

To do this, I’ve placed a PhysicsConstraint to simulate the physics of the frame hanging and a CableMesh to visually represent the cable (without physics). On my frame mesh, I’ve placed a socket on the eyebolt position.

Connecting the CableMesh was easy, I’ve attached it to the base object and the frame (specifying the eyebolt as the socket) and it was done, as it can be seen in the image.

Hovever, I’m having issues in doing the same with the PhysicsConstraint. I can attach it to both objects (the base and the frame), however I cannot specify the socket to attach it to. Right now it appears constrained on the center of the mesh.

I’ve seen I can specify instead a joint or a bone, but I don’t know how to set those and if it applies to my example (I’ve seen that to use bones I’d have to create a skeletal mesh and use blender to add bones, that seems like an overkill for my simple example).

How can I achieve this? Why is the socket working for the CableMesh but not for the PhysicsConstraint?

Thanks!