This still doesn't prove that you cannot have an ala carte decision concerning these experiments.
To broaden my point, and to put LET itself under possible question, the discovery of FTL travel could be interpreted as:
1) A violation of causality, and thus a violation of the physics of SR (which assumes causality).
2) A Lorentz violation, and thus a violation of SR, LET, and other Lorentzian theories.
I will concede though that, yes, you could say that Lorentz transforms, and not so much the idea of spacetime, is responsible for the notion that FTL travel implies causality violation.
I still don't agree with you that FTL travel somehow inherently violates causality. That is my point. There is no reason why FTL travel should imply causality violation, especially if discovery of FTL travel raises doubt about certain physical theories from which this notion arises in the first place.
In the name of Ockham's razor, I would give up "Lorentzian physics" before I give up causality.