Somehow, in our current design, the information must be stored in an object that exists:
IIRC that's what the layout context was meant for.
Perhaps, but I doubt it. If they was change to always get a reference to the parent layout context when they are created, and if they had a reference to the FObj, and if they was made available to the property subsystem, then they could properly be used for it.
I still think it is easier to use either the FOs or the LMs .