Polymerizes chitin, a structural polymer of the cell wall and septum, by transferring the sugar moiety of UDP-GlcNAc to the non-reducing end of the growing chitin polymer (Probable). ChsV and chsVb do perform additive, but not redundant, functions in septum formation. Functions not only in the maintenance of cell wall integrity under different osmotic conditions but also in polarized cell wall synthesis. Plays an important role in the complex infection process of this fungus