Earlier quoted context omitted.
All macs use the same compatible nand chips.
Is there any compatibility between generations, eg. harvesting NAND from a M1 generation machine to upgrade a M3 (or now M4) generation machine?
Apples segmentation takes place in the nand firmware. The firmware contains the location in the storage configuration. And this may or may not be rewriteable. Iboffrc has done a video explaining how some of it works. It's all from reverse engineering though.