The killOp command accepts only a single opId. If multiple operations need to be killed, this has to be done with multiple separate calls to killOp. This doesn't scale if there are a large number of problematic operations. By contrast both killSessions and killCursors accept an array of things to kill. It would be useful if killOp could be extended so that in addition to accepting a single opId, it could optionally accept an array of opIds instead.