You can reload and aim while doing parcool's fast run.

I think it makes sense not to be able to run while shooting/reloading, also the third person animations look really weird, don't know if its just TACZ or if Parcool takes a part in it, but when running its goofy and when crawling the animations are inaccurate, since reload animation or gun placement doesn't show actual reloading or even point the gun at the right direction, like in the image, this proves to be an issue specially on multiplayer since you can't know where another player is aiming most of the time, even when crouching (when not moving), aiming or not, the player looks like its pointing the gun down and doing a weird pose.