Quickstatements supports adding/editing StructuredDataOnCommons structured data to Commons files. However, it does add duplicate statements.
An example where this occurred is in this edit, part of this batch.
Description
Description
Event Timeline
Restricted Application added a subscriber: Aklapper. · View Herald TranscriptNov 25 2019, 7:25 PM2019-11-25 19:25:44 (UTC+0)
Spinster edited projects, added SDC General; removed Structured-Data-Backlog.Nov 25 2019, 7:35 PM2019-11-25 19:35:30 (UTC+0)
Restricted Application added a project: Wikidata. · View Herald TranscriptNov 25 2019, 7:35 PM2019-11-25 19:35:31 (UTC+0)
Spinster moved this task from Backlog to External tools on the SDC General board.Nov 25 2019, 7:35 PM2019-11-25 19:35:48 (UTC+0)