Appends new per-document column values (Questions) to an existing document set (SavedList) identified by the path id, without adding or removing rows and without modifying existing columns. Only the questions field of the body is used. Each supplied question is stored pre-completed so the NLP answering pipeline is never triggered, a QuestionBatch is created per grouping key pointing at the existing set so Curate renders the appended columns, and the new column selections are merged into the set's viewConfig.curateSettingsV1.queryParams.qSearchParams so they are visible on open.