First, thanks to everyone for the feedback. Much appreciated.
I already made it through QC after replacing this particular image from the initial submission batch.
I use Darktable for all the post-processing; the lens correction was already applied to this image. This should take care of distortions, transversal chromatic aberrations and vignetting.
I checked a few other pictures taken with this camera body and lens, and it seems that the combination of 70mm and narrow aperture (f/13) results in sharpness problems. Images with a different focal length or aperture seem to have better results.