I am not an experienced Forum User, so please feel free to reorganize this post.
Here my fairly simple to realize feature request:
Conversion of chord symbols to Nashville number system based on the actual chords and the given mode of the song. Can be arguable if every song has to be set up in major mode in advance or if the converter realizes e.g. A minor as the key and translates it to C major in order to show 6- correctly.
There are some posts on workarounds here in the forum already and for Sibelius there seems to be a plugin that does the job, but the workarounds given here in the forum are not really helpful for me because not everybody wants to learn that superior system, so it would be very handy to be able to switch back and forth.