>>26579557>>26579595Rotomdex offers advice on where to go next. The only time in previous pokemon games where you had to backtrack was to use Cut.
Seeing as we've only got four islands, rather than a large land-based region, we may have to go back and forth for story-related missions. Like, instead of going straight to each gym with a detour to stop the evil team at one point, professor Kuki has us go to one island, meet with someone, and return to him to proceed with the story. Go to one island, return to Kuki, go to the next island, travel back to the first island and go a new route, return to Kuki, go to the second island and find an item after finishing the first island. Something kind of like that.