Best SxS comparo standard for "natural color"/doubles is a large newt with the same EP/focal length. Then the saturation of the refractor stands out the color variation, independent of other concerns. Sort of like the way the breakout test allows you to quantify SA/correction with a star test.
Both are useful with refractors/mak/sct. Complements white light DPAC.
You might find that AT102ED star test shows tiny overcorrection - perhaps this affects "sharpness" ?
Oh, and as to eye oddities ... cataract lens replacements did enhance the high end of the spectrum in the past. And some red LED's emit junction noise as shortwave, which is why red plastic was used to minimize this. So yes altering the eye can make it much more sensitive to CA as well as register from stars/nebula elements of the spectrum that are different, not to mention the effects of the age "yellowing" of cornea/lens.