I'm not sure if this would be helpful or not concerning your original request, but on your EW410, you should be able to save an internal song as a MIDI file directly to a USB flash drive without having to save all of the keyboard settings as a USR file and then try to extract the songs from the USER file. I don't use MIDI too much and I'll admit that I am not very knowledgeable with it, but on my E433, I have saved an internal song (that I recorded on the keyboard's built-in sequencer) as a MIDI file to a flash drive, then had a totally separate keyboard read that song file from the flash drive and play it back.
The only concern, and something I am fuzzy on, is what happens to some of the tracks. As I understand it, the MIDI file can only be created using 8 melody tracks or channels, but a song that you record on the keyboard has 10 melody tracks -- 5 tracks that each can contain main and dual voices, for a total of up to 10 separate instruments playing. So I don't know if the extra 2 tracks are just deleted, if they are somehow merged with other tracks, or something else -- and I also do not know which extra tracks would even be affected. If you use auto accompaniment when recording the song on the keyboard, then I believe that it uses the other 8 tracks or MIDI channels available.