Very simple to understand: as long as you're aiming in the air you stay still. What stops aiming? Swapping weapons and reloading. So if the gun I'm using needs to reload, I'm suddenly cosplaying Icarus and plummeting to the ground. Making it so it doesn't reload your equipped weapon because single shot weapons don't work with it makes zero sense. Could have just put in the tooltip explaining that it reloads equipped weapon except those with a single shot.