Here is a .rte a file I created in Vroute which seems to work just fine in NGX 737.
I am ot sure if this is the same format as used for JS4100, but you can take a look and compare. Anyhow it seems to work in NGX. Could you please tell me how to export a rte files from EFB? I see only "Export as rt2 " in my EFB!
See the attached file!
Regards//