I think I can understand that about the earth’s orbit.
Pretend we found a log on Mars; another on a moon of Saturn and another on . . . oh, in honor of the movie . . . one of the moons of Endor.
Is it now conceivable, or not, that the decay rates could be different for each location?
That might be the case. However, C14 dating has always been dependent on location and altitude of the original organic materials' growth. Some areas have higher C14 levels than others. C14 dating is only as accurate as its calibration through other dating methods such as dendrochronology can confirm its accuracy as you go back in time. Once you go beyond the confirmation of such other dating methods, C14 dating accuracy gets more and more to be educated guesswork. In some areas, we have overlapping growth records that can take us back up to 20,000 years. In other areas the confirming wood tree ring record simply does not go back that far.
However, this variability of accuracy is NOT based on changes in decay rates. Those are assumed to be the same whether the items to be tested are in Asia, Norway, or Egypt.