I've been really enjoying this mod recently, but I've noticed that when you ADS with a gun from any of the ARC9 mods (I'm using Darsu's EFT ports) it doesn't move from the hip and just kind of sits there.

Using the customization mode with the use key also seems to break, the gun just sits where you would hold it without editing the gun.

Doesn't seem to happen in any other game mode, only when you're using the Half-Life Co-op one.