Correction: it'd not be Norinco but 208th Institute's job, though if the PLA decided to go the way the US does (perhaps some of you already familiar with that Chinese meme: 走美帝的路讓美帝無路可走) mod the furniture on the current grenade launcher kit to make it a stand-alone "thumper" similar in size as that of M320.However this is a bit OT to the QBZ191.
Obviously Norinco will if required cook up a dedicated mount and launcher. Likely modified off of either the launcher on the QBZ95 possibly redesigned akin to how FN changed the F2000 launcher to the Mk13 or the Launcher from CS/LR17 probably with a dedicated mount that like those on Army M4A1 with M320 would require an armorer.
That, again, is 208th Institute's job. Norinco is just the "department store" for Chinese arms export.