I certainly would not say I can prove it but I do think it is indicated in some way by current data.

Here is where the "You cannot prove a negative" comes in. What possibly could be posted which proves no test had ever been done. I feel therefore it becomes incumbant on those that disagree to post proof of such a test to falsify my claim.

I think it might well be possible to find tests that have been done and analyize the data to see if the motion to the CMB is reflected in it (if the tests are sufficiently documented to be able to verify test cnditions and timing (orientation to the motion to the CMB.

If not then I believe a linear accelerator could indeed be scheduled to look specifically for such correlation.

BTW: The maximum deviation in data for such an affect would be 1/2,000,000 (5E-7).

I believe so but it requires indepth consideration to see if it violates any observation or emperical findings.

If you accept that the trip time of the moving observer is fully accounted for by the dilated tick rate of his clock then it becomes apparent that no length contraction has occured.

What is being done is to take the view of the observer and his proper time as being equivelent t' = t such that mathematically you now have TWO choices.

1 - Conventional SR where spatial distance contracts. But that generates some rather uncomfortable if not impossible physical realities.

2 - The alternative is that the common sense idea that relative velocity means +v and -v are equal is in error. Here you have two factors.

a - In a universal sense +v = -v. Where "v" as a numerical value is not considered but only the universal distance covered in a universal elapsed period.

b - v is frame dependant as a mathematical conclusion of the ratios of the physical realities in that frame.

In the rest frame that is v = d / t

In the moving frame it is v' = d / t'

This does generate higher velocity calculations in the moving frame but that makes sense keeping in mind that the clock being used to time the trip is ticking more slowly.

The fact that it results in superluminal velocites has no actual impact on its validity in that SR causes superluminal velocites as well by contraction of many light years of space in relatively short time periods of time as one approaches v = c.

In the case of SR these superluminal velocites are shielded from observation by the creation of event horizons to the moving observer. That might also apply to the alternative view but the realitiy of that I think must wait for actual experiment to determine.