The gain that he may see will unlikely be observable in the short term…although it’s possible. BR is a long term game. In every complex system, the absolute least number of parts to do the task properly is the best. A moderator serves absolutely no purpose in BR. You don’t get extra points for your sound level. It’s extra parts and since it’s job is to contain pressure where there should be none….it will most certainly cause a problem at some point. Those that claim better or equal accuracy by using a mod are likely experiencing a benefit from its weight influence alone. Many guns can benefit from some muzzle weight….although you can also alter muzzle exit timing other ways with air rifles….like a simple velocity change.
You will often hear that someone lowered or raised their velocity and their gun improved. This doesn’t necessarily mean that the particular pellet being shot “likes” that particular velocity. That’s a massive oversimplification and completely takes out the entire rifle system from the equation.
I doubt any intelligent person ever said they came up with a great idea about improving accuracy that involved trapping turbulent air around a projectile recently freed from the barrel bore.
Mike