The highest you can get is 2¹⁶ if the '4' is 2 (65536) because that how many slots there are If the '4' is fouring, then it would be 2¹⁶×2 (2¹⁷) because the '4' is kinda adding an extra slot to it
It does never happen in game. The 2s always came out of places that wouldn't break the strategy. So, another FAKE video but at least he mentioned this is not a game recording.
4096 tile should be Pinkish Purple 8192 tile should be Amethyst Purple 16384 tile should be Pastel Purple 32768 tile should be Purple 65536 tile should be Violet 131072 tile should be Crystal Blue