So this is the motivation for "Bjarne's Alternative Cosmology
(tm)"?
Oh dear.
No Bjarne, the distance to the star is what it is, but it can appear different to different observers. Time dilation does that to people.
Yes this is true, distance varies for different observers, and this is why it is so logic that rulers must vary too.
However, your A and B won't have to disagree. If they are scientists, they can do the math and find out what the real distance is (and if they are not scientists, they probably won't bother about a few decimals).
Still rulers must be variants, at least for scientists.
So, sorry, you have not shaken the paradigm, you have just noticed something everybody has known for decades
.
No amigo, I was even thrown out of a scientific forum for insisting what everybody
should know. If the ruler is a variant GR will no longer be the same theory.
And this shows how intolerant and brainwashed that community really is