Either I am missing something, or the track length is ignored for file matching.

From what I found, the "Ignore track duration difference..." setting will only change the background color and within the "Matching" options there is nothing regarding the duration.

A checkbox "Consider duration when matching files to tracks" and a numeric field "Maximum deviation" would solve this issue.

I looked around the forum and also in the tickets but I could not really find anything:
PICARD-877 might be about the background color.
PICARD-768 is probably about this issue...
POST this is my forum post about this issue.

Outsidecontext suggested that the file will be used but gets a bad score. I am not sure how bad this score can get but my files get a green icon, and the album will still be a perfect match even if the similarity is set to 100%.