Nevermind, found it.
In short, the text describe the major modification is essentially change out the standard handguard to one that's similar to the DMR version, as the result is a leaner and lighter gun than the standard version.
It also acknowledge the modular nature of the QBZ-191, especially that the handguard can be swapped out for aftermarket kit. The manufacturer will roll out more custom handguard options tailored for specops requirement, such as handguard that has picatinny rails on all four sides.