My take on relativity is somewhat different; IMO, Special Relativity together with the Binomial Expansion is a way of defining interactions between two real number systems, with c being an arbitrary parameter (c=1 at the "zero point" energy in the parking lot at noon). What remains is the physical interpretation of what it means for ct to change to ct', which is governed by what I call "the fundamental equation of Special Relativity (1.1) in my document "the Relativistic Unit Circle" which then relates "spin" to the Binomial Expansion (and thus a proof of Fermat's theorem for positive definite parameters, as in STR before Dirac). From this, the relativistic expression of the Lorentz force can be derived.
Einstein's view of GTR then becomes a Newtonian view superimposed on a metric, but essentially a classical interpretation of geometric optics, where geodesics are conceptualized as "streamlines' in a partially Eulerian model (as opposed to LaGrangian).
If anyone would like to discuss this further (to see whether I have my head up my ***... :), take a look at the paper in my signature "The Relativistic Unit Circle", where I show (1.1) to be the foundation of ordinary muiltiplication, and why Fermat's theorem is valid, not only for integers, but in general for positive real numbers (since the Binomial Expansion is valid for positive real numbers).
It is (IMO, FWIW, YMMV) a foundational issue with a LOT of philosophical consequences.
OTH, (to paraphrase W. Pauli) I may "not even be wrong", but someone should contact Dr. Wiles about his proof... :)