While this would cause issues if people were playing in tournaments without sleeves, its really not different from how people have to handle double-sided cards in tournament play right now
Bypasses wall-matches like Cornerstone Ogerpon ex
Cards like Reanimate and Whip of Erebos bring cards back from the dead for a second go, and Winter's own delirium triggers the return of a permanent card from your graveyard
Everything Comes to Dust makes you check the entire board for creature types, but its a nice tech piece for decks focused on an atypical creature type
Several of the multiverses planeswalkers work together to fight the titans, and with the added power of Ugins hedrons, which significantly weakened the Titans, they finally managed to destroy both Kozilek and Ulamog, with Chandra dealing the fatal blow
The commander you control doesn't have to be your commander