Work has officially begun. Nothing to show yet but have an initial decision: Initial prototype location will reside in the Scene panel.
Stay tuned for more as things progress.
And as you might notice with recent posts I created about the outliner I’m thinking it would be nice to leverage that (that Outliner) either as the residence for layer management or (perhaps more properly) as an easy view component of layer manangment information. But more thought is required for that specific aspect.