HBM is independent of the DDR revision being used. HBM how the DRAM attaches to the chip. Really not sure what you’re trying to say.

HBM stacks multiple DRAM dies vertically on top of each other (typically 4-12 layers). It’s very different from DDR, especially during manufacturing because it has to be integrated with custom chips. Afaik, this isn’t available to Chinese foundries.. yet.

Thus, they have DDR available. Specifically, theyre using LPDDR5 so far.

But it’s still the same dies- the shortage is in the dies not the packaging, no?

It’s difficult to integrate as HBM and the density is very different. China wouldnt select 30x slower bandwith if they had a choice.