Amur/Lada class of submarines were a disaster in terms of their AIP system, not the rest of the sub. But if the sub was converted back to conventional diesel-electric without AIP, there is no reason for China to get this when China already has AIP submarines and the 039B is also a much bigger sub with the advantages of the size increase brings.
As for developing newer submarines, Chinese availability when it comes to supercomputers will give the Chinese an edge in doing CFD towards hull design.
As for developing newer submarines, Chinese availability when it comes to supercomputers will give the Chinese an edge in doing CFD towards hull design.