Based on the examples and comments, this looks likely to be a minor issue in real-world shooting.

Marks on the sensor filter stack tend to show most on plain, evenly lit areas and at very small apertures such as f/32–f/36. Since your mark is barely visible even under those conditions and only becomes obvious with extreme contrast adjustments, it may be invisible or nearly invisible at f/16–f/22, and often not noticeable at wider apertures.

In normal landscape images, subject detail usually hides faint defects like this. One responder also noted that part of what you see, especially near a corner, could be cleaning residue rather than a true scratch.

The practical test is simple: shoot a range of real subjects at the apertures you actually use, process them normally, and see whether the mark appears in finished images. If you only see it in extreme test shots and exaggerated edits, it’s probably not worth worrying about.

So: if it doesn’t show up in your usual workflow, you can likely ignore it. If you frequently shoot plain backgrounds at very small apertures and the mark is visible in final images, then repair may be worth considering.