The way I would have gone would be to define the standard to support both, such that the two sets of codes MUST be considered semantically equivalent, but that generation tools SHOULD prefer to generate the control codes for new files.
This way people can initially use the visible glyphs while editors don't support the format, and this will always be supported. But, as editors add support and start to generate the files via tools or manually in tabular interfaces where the codes themselves disappear, usage will automatically transition over to the control codes.
This way people can initially use the visible glyphs while editors don't support the format, and this will always be supported. But, as editors add support and start to generate the files via tools or manually in tabular interfaces where the codes themselves disappear, usage will automatically transition over to the control codes.