Cantonica is never clearly established as a desert planet onscreen. All the audience sees is Canto Bight. Besides, I don’t really see the point in this change. Of all the planets you could change it to, why Cantonica? You say it drives home TLJ’s themes but I just don’t see it.

As for Rose’s absence…are you sure we can’t just roto her into the wide shots and give her a line or two? It’s not like Finn or Poe are contributing much to the fetch quest, so will anyone even notice her lack of contribution?