This is super impressive! It's a cool POC, although it is already clear that it would be feasible for Apple to put M.2 slots in Macbooks if they wanted to.

I wonder how much it would cost to have someone replace the BGA NAND chips in my Macbook. Apple charges $6-800 for a 2TB upgrade for a Macbook (depending on whether it's a 250 or 500GB drive originally). Someone would have to be able to do it for like $2-300 for it to be a feasible upgrade, especially considering that my warranty would be void. I assume there are people overseas who could do it cheaply. I assume it would be fairly quick for someone who knows what they are doing.

M.2 slots? M.2 SSDs have drive controllers on them, but in the Apple Silicon world, those controllers are integrated in the SoC.

They should absolutely not reuse the slot type for incompatible products.

They should make one though, their storage offerings are lame.

Consider that by the time you’ve ran out of storage you may have also ran out of your warranty.