Some online journals paginate each article individually, i.e. each article starts at page 1. Using page ranges for identification purposes is not useful in these cases, that’s why some style guides require article numbers in these cases: https://sblhs2.com/2018/05/03/electronic-journals-with-individually-paginated-articles/; CMoS17 is similar here (CMoS, 14.174, p. 832).
This has already been discussed on the Zotero forums, but I don’t know if anything has come out of this?
Shouldn’t this be handled somehow with CSL 1.1?