As best I can tell, there's no good reason for the user to provide a field name for Custom MediaFront field types. The instruction "Enter the machine name for the field you would like to bring into the media player" is a bit ambiguous. Is this the existing machine name of the field the user has already selected? Then why, if the field is already selected, does the user have to identify it again? Or if the user is providing a different name for this field, what's the point? Why not use the existing field name?

It just seems that, if MediaFront used the existing machine name for the selected field without requiring user input, an unnecessary and confusing step could be eliminated.

BTW, if the user uses a custom name of "title," uses a title field from a relationship, even if that field is given a different custom name, OSM Player gets confused and falls back to the default "Sample Title."