OK, so much of it wasn’t written by Mozart, and indeed it is good to see a quite comprehensive list of editions at https://musicbrainz.org/work/3b11692b-cdc7-4107-9708-e5b9ee386af3. I have a couple of recordings, neither of which specifies an edition, so I’m using the catch-all (https://musicbrainz.org/work/5ba9868e-f053-4520-8957-6a9fedb2455a). I notice that this, along with the other editions is not divided into the eight sections (Introitus, Kyrie, Sequenz, Offertorium, Sanctus, Benedictus, Agnus Dei, Communio - see https://en.wikipedia.org/wiki/Requiem_(Mozart)), but rather is presented as a “flat” fourteen movements.
I would prefer the structure to be explicit, but am loath to mess with such a famous work
If I did change it, I’m also not sure whether I would just change the catch-all, and where that would leave the other editions. Whatever, I would appreciate a bit of input/advice from those with more experience in these things, thanks.