|A parallel complete-system to find co-jectures:|
The inverse-square-law of gravity and mass motions therein is akin to the inverse-square-law of electrical charges...
The speed of the gravitory equation is esteemed to exceed the speed of light by many orders of magnitude though the speed of gravity waves is exactly the speed of light: This implies that the gravity 3D-dimple around a gravitory mass moves with said mass while maintaining its inverse-square-law geometry which maintenance must be done at the speed of light-and-gravity-waves...
There is in this construction the inherent-intrinsic obviosity that the 3D-dimple cannot be perfectly-inverse-square-law if-or-rather while in-motion: The maintenance of said geometry would have to keep-up-ahead against the speed-of-light-and-gravity-waves and by time it did -it does- would be late-er in the geometry;-- And this portends a new shape and more-importantly possible compression of the 3D-dimple making it steeper which already coincides with the theory of 'steeper-is-more' gravity; And this portends the (forward)-'projection' of the local-center-of-gravity as-if-it-were leading the gravitory mass ...
A dominant argument in the speed of gravity is that co-orbiting gravitory masses must 'see' an exactly-perpendicular force 'pull' of gravity if they are to remain in perfect co-circular co-orbits concentric 'around' about their co-center-of-system-gravitory-mass, but which cannot be 'true' if the directional-speed of gravity is late-behind on either circle, where expectably each would accelerate toward the other's late-position and so away from their system center, unless revolving gravitory masses were radiating gravitational energy to the cosmos so-compensating acceleration-away-from-each-other: gravitational-'phlogiston' sort-of, and the implicit theory that all cosmic objects are shrinking and so-apparently the cosmos viewed from shrinking viewers is expanding.
THE VELOCITY AND ACCELERATION OF MASS-HOLES:
'mass-holes'-- 'black-holes' but we're doing everything we can to define them 'not-so-black': x-radiation from debris rings, virtual photon-pairs, straight-out escaping z-ray photons sufficiently narrow as to avoid much spreading and falling back, quantum spin-up elevators in the superfluid cosmic aether in which the speed of light is less retired, the renormalization within the condensed mass that creates a new micro-cosmos, and the yet-curious fact that the holing supernova core condenses to a spinning ring or disk of unwound self-destroyed (*) neutron-essence having but half the self-gravity of a sphere and having finally reached the speed of gravity where the ring collapses no further as it tries to accelerate and pull itself open again: That's the bottom value of a 'singularity' ... If we were on the inside we'd see only the sphere of the mass-hole not the ring moving at light speed.
* (The neutron-internal positronic and electronic charges have been reduced to common values and unraveled to y-rays, and opposing neutron-internal motions have found their way to the opposite side, and the total mass being the same converted from potential gravitational before the collapse has become less-mass, and collapses no further.)
The question is asked whether the inside of black-holes 'mass-holes' can respond to the gravitational field applied on the outside as that field changes at the speed of light and gravity which has slowed inside. But the answer is as obvious as the frictionless cart of basic physics theory: The innards of a mass-hole however small, is yet mass, and that mass is mass-energy, no longer atomic or nuclear but yet-whatever moves with the movement of massive objects and even 'massless-energy' photons and moves at its slower speed of light and gravity, but, turning -acceleration perpendicular to its velocity- adds energy crosswise, as readily as before it slowed ... It cannot be accelerated nor decelerated forward or backward than light speed, but, turning is easy.
The central mass may lag inside its mass-hole, but overall keeps-up till it reaches the real question: Can mass-holes travel near the speed of light in the external frame? Probably not, but the experiment might be to locate mass-holes related to galaxies at the redshifted edge of the cosmos, and check for less, redshift.
A SIGNIFICANT 'OTHER' QUESTION:
If correvolving masses radiate gravity-waves carrying 'potential' energy, From what does that potential source?-- It equates gravitation to mass-energy and reduces the cause of gravity to the presence of mass-field ...
But I note that the notion of photons slowing in a gravitation field is obscured by the fact that their energy must therefor convert to energy-mass in the mass-field which is itself not slowed but radially standing: The photons become part of the field and only the remaining mass-energy of the reduced photons perpendicular to the radius is slowed apparently and continually spirals in. Redshift of photons passing by a star cannot be synchronous but asynchronous-particulate.
Final comment: gravity, and electronic charges, are not forces but phenomena of constructive and deconstructive, objective, coincidences and anticoincidences ... in 'very large' aggregates.
OTHER COSMIC NOTES: 
1. The dynamic 'Spinning Casimir Effect' pumps-out the super-vacuum of--
1.1. The 'Static Casimir Effect' attributable to two terms:
1.1.1. Atomic-level bonding, both ionic and covalent, positional adjustment-flexing-stretching moving opposite charges closer and overall cumulatively slightly attractive
1.1.2. (standard) Closing-out the low-frequency components of the cosmic-aether-quantum-field zero-point-energy oscillations, reducing the internal-blackbody-radiation-pressure
1.2. by the 'Tesla Close-Parallel Spinning Disks Pump' effect
1.3. Pumping-out super-vacuum across a surface might pull the surface toward normal-/lower-vacuum space
1.4. Faster-spinning variants might include magnetic-sweeping-out the super-vacuum between close-parallel plates
1.5. This note is for the development of one or more project Sesquatercet sci³-fi screenplays.
A premise discovery under the title,