You can enable The route variation in The play menu ✌️ I don't know this stacked Stone tule? Where did you hear about it?
I used to play this game a lot on android, it had 3 or 4 different posible rules, and each tiles had different mechanics to them, one of them allowed you to stack pieces on top of each other, if you had more than one on that tile, they couldn't be removed, so these tiles were key in order to advance in the race but also to block the opponent. I triad the Egyptian game too but this one is much more fun.