We have a requirement for multiple EXT-X-MAP tags within a single playlist file (one tag per segment). https://github.com/grafov/m3u8/blob/master/writer.go#L667 allows setting Map on the current Segment whilst appending, but ultimately only the Map attribute of the Playlist is encoded https://github.com/grafov/m3u8/blob/master/writer.go#L367 , Segment.Map is being ignored.