"Attach socket" with Oculus Interaction SDK

I'm trying to recreate the "attach socket" (XRSocketInteractor) from Unity's XR Interaction Toolkit.

Has anyone had any success? I've read through the documentation but can't come up with a simple way to do this. I've even tried writing my own script with an OnTriggerEnter() using both

grabInteractable.AddSelectingInteractor(grabInteractor); and grabInteractor.Select();

but still haven't got a complete snap attach..

I've gotten the grabbable object to turn green (be Selected) seen with the "Interactable Debug Visual" script but the object doesn't "auto move" to the transform point and I'd rather see if there is indeed a proper way to do it.

Any ideas?