When using the “use gear X” keybind with the ACIG it will equip the ACIG and require R2 to throw.
Where with the frag grenade it will instantly throw on a press and cook the grenade on a held press.
The way the frag grenade is handled is more intuitive for projectile gadgets in general, especially for the ACIG specifically because of how you want to us it; as well as the fact that keeping gadget controls similar to each helps with muscle memory.
So please change the way the ACIG interacts with the “use gear X” keybind.