@olf, good point. There was a statement in Fonts module description, but I have added now a separate paragraph stressing it.

Fonts module is needed only if you use Mapnik backend.

Mapbox GL has the same fonts, but they are packaged differently, in Mapbox GL specific glyphs. These you download via OSM Scout Server and, in reality, they are larger than TTF fonts used by Mapnik. However, you probably store Mapbox GL data on SDCard and don't care much about it.

As for altering the messages - I'll take a look. I will link them to the selected profile. Opening an issue for it