[2020] Option to remove hip fire icon while aiming

Oh, you mean the crosshairs. You don't want the crosshairs visible while aiming down the sight of the gun. I don't think there's a way to do that, but maybe there's a mod that does this.

I do think it's an unusual choice, and I recall others wanting it changed.

Removing it from ironsights is pretty easy.
Just change true to false.

To remove it from regular view, you probably need a DMT mod. Which means that it won't likely work with EAC. Stallionsden or Khaine have probably made a UI mod that removes it.