I know it is possible to obtain flats instead of sharps for selected notes for one musical editor (chord, chord-seq, etc.) at a time, by changing the editor scale
OpenMusic Documentation - Tonal Display
See also the questions
The Flat Symbol in Score
flat and sharp in a chord-seq
But is there a way to obtain this in all musical editors at once?
Maybe by modifying the “default scale” (where to find it)?