With tools like 3DNUS (3DS Nintendo Update Server), users can download official update files by entering the title ID (for Omega Ruby, it’s 000400000011C400 ). This method downloads encrypted .CIA files directly from Nintendo’s servers, which is technically legal if you own the base game.
Search for "Pokémon Omega Ruby Update" or navigate to the "Updates" section in the eShop menu. Pokemon Omega Ruby Version 1.4 Download