Though entirely theoretical, the solution to the twin or clock paradox reflects the different application of the Lorentz transformation in the two alternate theories (MLET vs. SRT). Part of the problem with addressing the twin paradox of a traveling and stay-at-home twin is that so many different mutually incompatible solutions are offered within SRT. However, as far as I am aware, all the solutions claiming to be consistent with SRT involve changing inertial frames when the traveling twin turns around. The specific solution given by Ohanian  seems to be the most consistent with other applications of SRT (particularly with the Thomas precession above). Ohanian says that, when the twin turns around at the end of his journey, he causes a hyperbolic rotation of the lines of simultaneity around his origin. Again, this involves magic because the position of any light signal in transit must suddenly adjust in both position and time to be consistent with this SRT solution. (This argument has been presented in greater detail in a prior paper .)
The solution to the twin paradox in MLET is the soul of simplicity. Pick any inertial frame you want for the twins and treat that frame as the absolute frame. Then stick with that frame as the isotropic-light-speed frame for the entire trip. Never change frames. Simply let each clock run at a rate consistent with its velocity in the chosen frame. The same observed slowing of the clock or decreased aging of the twin who makes the round trip relative to the stay-at-home twin will be observed independent of the chosen isotropic-light-speed frame.
- Ohanian, Hans C. (1988) Classical Electrodynamics, Allyn and Bacon, Boston, pp 184-186.
- Hatch, Ronald R. (1999) “Symmetry or Simultaneity,” Galilean Electrodynamics, Vol. 10, No. 3, pp 51-55.