aka, china wants to have all the advantages of a reserve currency, without suffering any of the disadvantages (yes, there are disadvantages that the US suffers from the dollar being a reserve).
I wouldn't say they would have all the advantages of a reserve currency. They will still have to find a way transform the foreign currency they accumulate into useful stuff. I think their primary concern is avoiding the dollar, since they quite a big exposure to it, and after they have seen what happened to Russia, their not too keen on maintaining the status quo.