I don't think it is all that important to try to force players to travel if they don't want to. I never stay at one town in any game even if it has all tiers in it. And I know others who also course to travel because they want variety. But for those who prefer to stay on place, trying to force them to move with a mask design probably isn't something they are going to want to play on. Just my opinion, of course.
There are also other options to get players traveling that are more feasible. Darkness Falls does it with their quests requiring going to different places. As long as those places aren't next to each other, you need to travel. You can also do something where trader progression requires using all traders and then make traders 1-2km apart. There are various options that would work for that goal without trying to do something that the game design for tiles and prefabs isn't really designed for.