Hello!

Today, I've been wondering about a tournament shortcut and whether if it would be fine on any REL.

Let's say a player controls Urza, Lord High Artificer and has a million blue mana in his mana pool. Urza's ability reads: 5: Shuffle your library, then exile the top card. Until end of turn, you may play that card without paying its mana cost. Can the player propose a shortcut, in which the deck will not be shuffled, but the top card will be exiled each time he wishes to activate the ability? After the first shuffle, the deck is already random, and the only thing that changes is the top card, which gets exiled. Assuming no other effects revealed any information about the position of cards in the deck (e.g. Lantern of Insight or Mystic Forge), would skipping the shuffling be legal?

Would love to hear your opinions and rulings!