I didn't see the page on the official site. The tracklist came from
https://special.canime.jp/comiket/96/ and all the credits were copied from PCCG-01706 and PCCG-01707 assuming it to be the same instrumental recordings.
For 11 I had copied the credits from an incorrect track, M-10 on PCCG-01707 (which didn't have a separate chorus credit) rather than M-02. I fixed the credits for 11, but I think the strings arrangement credits can stay since I don't see anything about the songs being rearranged or rerecorded?