A cultural Lorentz transformation, interesting....
Nothing to wink about. You're the one who chose relativity in physics as a metaphor for relativity in morals. I'm just pointing out to you that the implications of this metaphor are not even close to what you think they are.
For one thing, if you run a correct measurement relative to one frame of reference, and another correct measurement of the same phenomenon relative to another frame of reference, the measurements will differ by no more than a coordinate transformation (Galilei or Lorentz, depending on the velocities involved). That's a lot less wiggle room than you claim for moral judgments in different cultures.
Second, the same laws govern the outcome of any given physical experiment, no matter what frame of reference you measure it against. That is emphatically
not the case in morals as you describe them.
Not untypically for a moral relativst, you are trying to recruit the authority of the hard sciences for your moral philosophy while refusing to play by these sciences' rules and ignoring their findings.