The relationship between Gallé, Burgun Schverer et Cie, & Désiré Christian is described in Arwas (1996) The Art of Glass, pp. 19-26. (see Here
) Sadly no direct reference is given but Traub’s work is not included in the bibliography.
Arwas suggests that Désiré Christian was to work 'in accordance with with Gallé's specific and detailed drawings, moulds and instructions.' (Arwas 1996, p.22). I would have thought this to be fairly normal prcatice, particularly, as, according to Arwas, Gallé had had a relationship with Meisenthal dating back to 1864.