If you have a license for client, I have a playlist editor that includes sorting at
http://subfiresuite.com/pl/ (or
https://subfiresuite.com/pl/ if you're secure server).
Not terribly well documented right now I know, but functional. Simply log in (it talks directly to your server, my IP host doesn't see any of your traffic at all), click Open to select the playlist, and the sort options are at the top, along with ability to make it shared v private with other users on your server.
The design is a kanban board (a-la "trello") for dragging items to the playlist in the order you want. Dragging across editable playlists will remove the file from one to list it in the other. Dragging from read-only browsing sources (albums, playlists for browsing, music directories) will add to the playlist, the original source column will immediately revert to its original state. (so no, this isn't a way to move your files around physically on the hard drive

)