Maps are always about interaction between visual elements and informations. If your purpose is to have an informative map, known languages are obviously better. If your purpose is to produce a piece of art, to suggest questioning, to create an atmosphere, to call mystery or to propose a riddle to solve... then everything is possible. I can confess my heart always melt a little when I see a map with any kind of cryptic alphabet ('love them a lot ^^), being imaginary, coming from old ages or foreing languages. But I also know it's not always appreciated, depending on the context. A matter of taste, I guess

Anyway... you already know what I think about your work, IC. You're among the giants, and I'm always a fan : those close-ups are just a candy for eyes ! ^^