A user with the Global Edit role cannot Add Approver/Watcher/Comments to the Approval Graph. Even if she adds herself onto a specific eGC1 with R/W access, she still can't change the graph.
A reviewer for the Org Code Receiving Funding or the PI Units can still add an approver/watcher/comments to the approval graph. Owners can also add nodes to the graph. Where necessary, we can imitate a user to add them on. Providing a fix to the Global Role will be considered for a future SAGE project.