I understand your concern and I accept that there may be a fundamental ‘lack of purity’ in the way in which Canon designed the lens. Nevertheless, I do not believe my particular lens is ‘bugged’ as you put it - it would appear to be something that is common to all RF 24-240s.
I agree that the RAW converter cannot guess what is in the corners. But Canon DPP; PL3 and the image on the camera screen show a correct, adjusted (and obviously slightly cropped) image.
If PL3 can do the proper adjustment and PL4 cannot, then I cannot understand why you deduce it’s an issue with the lens rather than an issue with PL4.
@mwsilvers
Will DXO staff automatically respond to this thread, or do I need to raise it as a support issue?
Thank you