I would look into Fresh Reviews channel on youtube, he is probably the guy who tests the most IEMs for competitive gaming and is actually somebody who plays at a high competitive level, so I´d value his opinion over some audiophiles who casually play.
You should be aware tho, that the perception of IEMs can differ quite a lot from person to person, because our pinna is acting as a natural filter, which is changing the sound before it goes into our ear canal. IEMs will go directly into our ear canal, so they bypass our pinna/filter and the manufacturer of the IEMs will have to guess how your pinna affects the sound. But everyone has different ears, so thats basically an impossible task, thats why you probably won´t get around trying different IEMs to see what works best with your ears. So just because somebody says IEM A a is a better than IEM B, that doesnt necessary have to be the case for you.
That being said, I actually had a good experience with Fresh Reviews recommandations, I´m personally using the Truthear Zeros and think they are really good for gaming, I still think you can get something better if you go with open backs like the HD560s or Tygr300R, but thats obvious not an option for tournament play. However, I would rather use the Truthear Zeros than any other closed back headphone/headset I have heard until now.
You also have to look at your sound settings in the game. I know a lot of people use the “night mode” preset, but honestly i think thats just terrible. It lowers the dynamic range, which makes everything sound close to each other in volume, which results in worse soundstage and depth perception. So I would keep that at studio reference or headphone.
Dolby Atmos should be on too, unless your ears really dont work with it and it fucks up your ability to tell directions. But if they dont work with atmos and you are forced to use stereo, you are already at a competitive disadvantage anyway, because other people have an easier time to locate stuff just because their ears works better with atmos.