It could be could to add the fact that developper can add markers on animations to follow a point on the model.

The markers could be read in the code.

It can be useful to make an item renderer follow a point on the model when an animation is playing

How would this work?

You could add markers with a name and a position like bones in the animation file, and with the AnimationState you could do state.getMarkerPos(Name); and it returns the position of the Marker at the current frame of the animation

What's to stop you from doing that already with bones?

I don't find how to get bones position in the code

Look at the getWorldSpacePosition and similar methods in GeoBone