I think the most common scenario it is convert one byte character set to UTF-8.
So maybe posibibility putting parameter which force replace one byte character set (set by this parameter) to UTF-8 (what is allways possible).
For example we have multiple bases with WIN1250. When we set parameter for example: -force_convert=WIN1250 for gbak, it will convert all meta fields (tables, procedures...etc) and data in this fields to UTF8.
It could be very usfull functionality.
Is it possible?