Like I sad in the post the k525‘CA is better than k624. But keep in mind K525 is 3k price range. In that price range there are ZP5，NF 5-25，NF 7-35，SB PM2 and every one of them will have better performance（good fov and less CA）than k525 even in max mag setting. And like you said it will run under 18x I truly believe you. I just can’t convince our members to spend their hard work money to buy a “5-18” scope when their had much better choices.That 1000 yard Tangent Theta image is truly impressive.
I will state that my K525 experience is not the same as @Msaon308 , but mimics more of @DellaDog 's experience. The image does deteriorate at anything above 18x. I typically run mine in the 12-18 mag range and the image is excellent.
I could not use a K624 because of the CA, believe me I looked through several and tried, which is ultimately why I went with an AMG instead. I sold the AMG to fund the K525 and do not regret it thus far. Yes, CA is still present but it is not nearly as bad as the K624 and is better than the k318. I would put the CA on par with what I saw in my T5Xi.
As far as image clarity/contrast/resolution I would put it as superior to the AMG. I have a simple test I run, there are power lines at ~700 yards. On those telephone poles are tags, about the size of an index card, with numbers, barcodes and labeling. Depending on how much I can make out on those pole tags determines to me the image quality. I was able to decern more with the K525 than the AMG.