For use in (physical) gaming, you'll want to err on the side of legibility. The script font IS period-appropriate, and it does speak of elegance of craftsmanship, that it's a serious map, not a quick scribble by a questionable cartographer ( speaking in-game, in-character). It would even be reasonable to print out, IF your original file is high enough resolution to print at 150-600 dpi, assuming the map sheet to be between 1.5 to 3 ft square. Like you see here, at small sizes this font goes illegible from pixelation faster than some simpler fonts would.

Is the file you posted at full resolution?

Used as a digital map, don't worry too much about needing zooming, just ensure features one would refer to at full size are legible at full size - say continent and ocean names. If one is filling a screen with a continent, maybe that's all you need to read minor cities, rivers, commentary at.

Keeping in mind how your in-character mapper could work; one cannot use an infinitely- tiny quill pen nib with real ink and paper...