Akinbo,
Einstein allowed a new logical SR postulate interpretation in his 1952 descriptions, distancing his theory from it's old interpretations as he knew;
"The history of theoretical physics is a record of the clothing of mathematical formulae which were right, or very nearly right, with physical interpretations which were often very badly wrong." (Jeans 1981).
An interpretation of a theory is well recognised at NOT the theory but often a cocoon of woolly confusion, or "near-contradictions and excess baggage" (Wilczec 2012).
As Mach said; "If, however, we so interpret it that we come into conflict with our experience, our interpretation is simply wrong."
So lets drop ALL preconceived interpretations of the postulates. (That's YOURS TOO!) and see if they CAN be logically interpreted consistent with his 1952 constructions.
PoR; "The phenomena of electrodynamics as well as of mechanics possess no properties corresponding to the idea of absolute rest." (same as the English; "..laws of electrodynamics and optics will be valid for all frames of reference.."
I suggest that becomes entirely logically consistent if we consider each 'inertial system' ('frame of reference') as a 'local region of space', such as that encompassed by a bunch of electrons, with a single assignable group state of motion K. i.e. a 'centre of mass' rest frame. Smaller ones (K') are in relative motion within greater ones, so WITH domain boundaries. That's what the DFM invokes and finds perfectly consistent. It was only woolly prior assumptions that 'hid' it!
"Light is always propagated in empty space with a definite velocity c which is independent of the state of motion of the emitting body"
That then goes almost without saying. If in motion through some background field in state K, the emitting body has some state K'. However large or small that system K' is, when the emissions leave it to propagate in the background system K they change speed at the boundary (TZ) to then do so at c in and wrt the new system rest frame K (so Doppler shifted).
Again, only woolly preconceptions hid that logic.
The logical system is 'Truth Function Logic' (TFL - see my 2012 essay) which applies to 'propositions', and brackets in arithmetic. Everything within a bracket relates ONLY to that bracket. We can have infinitely many bracketed functions within bracketed functions, hierarchically. NO COMPONENT WITHIN ONE CAN RELATE DIRECTLY TO ANY IN ANY OTHER!
Consistently applying the same rule for inertial systems then allows Truth Function Logic to apply to the postulates. However the familiar old interpretation is falsified! (perhaps why AE's 1952 paper was subjugated!). I hope that throws light on my comment that seemed to upset you so much.
Best wishes
Peter