Using an already updated 3DS ROM file (often named "Pokémon Omega Ruby (USA/EUR) (Update 1.4) (3DS)") is usually the most convenient method for a "better" experience. Conclusion
A: This is a gray area. Patching a ROM that you own is generally considered acceptable for personal use. However, downloading a ROM you do not own is a violation of copyright law. This guide is for educational and informational purposes only.
Look at the bottom corner of the game title screen to make sure it displays the 1.4 version number. If you want, tell me: Are you playing on a PC emulator or a real 3DS console ?
ROM hacks based on 1.4 often allow players to catch all 721+ Pokémon (available at the time of ORAS) in a single playthrough, removing the need for trading with Alpha Sapphire.
: Scale the game up to 4K resolution (10x native) to eliminate jagged edges entirely.
The 1.4 patch is the most stable version of Pokémon Omega Ruby. It makes several critical improvements to the original game code:
Pokémon Omega Ruby was already a masterpiece. It took the GBA classic and gave it the 3D makeover it deserved. However, the term represents the community's desire to perfect that masterpiece.
: All 721 Pokémon (up to Gen 6) are obtainable in a single playthrough. Increased Difficulty