Currently, the Text Language is set at the level of the device. The selected Text Language is applied with any profile.
Experimenting with my own maps, I changed the meaning of some POIs (e.g. 0x2a01 to "Indian restaurant" - I do not need a category for "American Restaurant"), I created my own ".gtt" file which lists the now correct text for those changed categories.
But of course, with Third Party maps, that's wrong - there the "original" setting is still required.
Hence setting the language at profile level could do the trick.
