According to Q-FFF Theory, Black Holes have NO inertial mass, only gravitational mass, by the inflow of energetic oscillating vacuum particles.
(See Casimir effect between plates close to each other.)
Why? Because black hole nuclei are assumed to be String Nuclei instead of atoms.
How Both masses are created both, Atom nuclei and Black Hole nuclei.
If Ball Lightning an Comets have black hole nuclei then we see differences with Super Nova and normal matter stars.
If Galaxies are speckled with black holes of different sizes, they have two sorts of gravity.!!!
A: Casimir oscillation effect based Vacuum Pressure.
B: New Graviton Pressure from atomic mass. (left below.)
Inertia os based on the resistance of atoms with the vacuum and the Lorentz Polarization of each atom deformation ( pear shaped)
The so called unresolved FLAT rotation of galaxies seems to be the result.
Rotation curves explained by the non inertial black hole nuclei
without equivalence.