Since what happens past the Event Horizon is unavailable to us with our present understanding of physics, I realize the interior could be anything from a point to a volume equal to or just smaller than the Event Horizon…or any size in between.
The classic “Black Hole” has a “structure” proposed by Schwarzchild…commonly accepted by the scientific community.
The afore mentioned Gravastar proposed and formulated by Mazur and Mottola as an alternative to the black hole.
Both are solutions according to General Relativity and operate the same way “outside” the event horizon.
It simply occurred to me that a construct based on the Planck Scale as a metric could place an ultimate limit of “smallness” using known physics.
Before Max Planck formulated the quantum…h or h-bar…scientists assumed energy was emitted or absorbed on a continuum.
If energy can be reduced to discrete “chuncks” like photons, maybe density can, too.