WannabeNetwon
I won't pretend that my interpretation of SR isn't contentious -- in fact, I'd go as far as to say that it's a minority position. However, I will continue to passionately advocate for it because it is the correct interpretation. (Incidentally, it was in poor taste that you accused me of being ignorant of the literature in the philosophy of relativity. I've read most of Harvey Brown's work on the matter, including his book
Physical Relativity, and have been thoroughly convinced by his arguments. On the other hand the papers countering his position, such as John Norton's "Why Constructive Relativity Fails", have been very feeble replies in my opinion.)
You begin by asserting that
In other words [length contraction] falls out of chronogeometric assumptions of SR whereas [in the Lorentz ether theory it] is a consequence of dynamics.
It's worth noting that, despite how confidently you state it, this interpretation of length contraction appears nowhere in Einstein's writings (at least that I'm aware of), even after he was introduced to Minkowski's work and even after his formulation of General Relativity. To the contrary, after Pauli wrote his review article on relativity, which contained the passage
Should one, then, completely abandon any attempt to explain the Lorentz contraction atomistically? We think that the answer to this question should be No. The contraction of a measuring rod is not an elementary but a very complicated process. It would not take place except for the covariance with respect to the Lorentz group of the basic equations of electron theory, as well as of those laws, as yet unknown to us, which determine the cohesion of the electron itself.
, Einstein enthusiastically praised it, writing that
Whoever studies this mature and grandly conceived work might not believe that its author is a twenty-one year old man. One wonders what to admire most, the psychological understanding for the development of ideas, the sureness of mathematical deduction, the profound physical insight, the capacity for lucid, systematical presentation, the knowledge of the literature, the complete treatment of the subject matter, or the sureness of critical appraisal.
For what it's worth, Eddington, who was responsible for introducing relativity to the English-speaking world, wrote that
There is really nothing mysterious about the FitzGerald contraction. It would be an unnatural property of a rod pictured in the old way as continuous substance occupying space in virtue of its substantiality; but it is an entirely natural property of a swarm of particles held in delicate balance by electromagnetic forces, and occupying space by buffeting away anything that tries to enter.
I hope these quotes convince you that the interpretation of length contraction, time dilation etc. as "geometric phenomena" is quite recent.
It's also an unsatisfactory interpretation in my opinion. To see why, we first have to ask ourselves, what is geometry? Without going into the level of rigor that would satisfy a mathematician, a geometry is a collection of things called points, obeying certain axioms, along with a way of assigning a number for every pair of points, this function being called the metric. Special Relativity gives us a way of creating a spacetime geometry, with events serving as the geometry's points, because the quantity ##\eta_{\alpha\beta}\Delta x^\alpha\Delta x^\beta## serves as a useful metric due to the fact that this quantity takes the same form in all inertial coordinate systems.
But here's the key point: the only reason we assign a such a metric to the set of events is because the laws of physics are Lorentz invariant. Otherwise, the quantity ##\eta_{\alpha\beta}\Delta x^\alpha\Delta x^\beta## would play no role in the laws of physics and hence would be completely useless. In other words, it is the symmetry properties of the dynamical laws of physics that create a spacetime geometry, not the other way around. So to explain length contraction in geometric terms is an indirect way of explaining it in terms of the dynamical laws of nature.