Years ago I composed a piece of chamber music that included an Eastern European-style pan flute (Romanian or Hungarian, I don't recall which). It was a large one, with a 3-octave range from G3 (the one below middle C) to G6. I asked the flautist if he wanted the music notated in concert pitch or down an octave like a piccolo. He preferred the latter, so that's what I did. I even used bass clef for some passages, since the written range was down to G2.
I want to publish this piece now, so I'm wondering how other flautists who play similar instruments like to read their music. Concert pitch or transposed? It occurs to me that the instrument's range is much closer to that of a standard flute, which reads concert pitch, than a piccolo.