Interesting if true.

Yes, exactly both.

would the design stop working if it got too large?

I mean, then just make multiple units and combine them. Much like one Tesla car battery consists of 4680 battery cells. And since we don't need desalination compact and mobile, it could be 4680 suitcase-sized units spread along the coast. The water output can easily be combined.

But dealing with the Brine probably becomes a real challenge if scaled up, no matter how.