Mouse smoothing is already disabled by default (m_smoothing "0"). m_smooth sets the number of frames, between 1 and 8, that mouse movement is smoothed over, when smoothing is enabled (m_smoothing "1").
Thanks, I figured out the issue. It wasn't working because I had entered another launch parameter as well. Seems the game will only apply one at a time.
Is the calculator broken? Changing between All w/ 2x Zoom, 3x Zoom, and 5x Zoom doesn't change Zoomed Sensitivity Scale at all, and converting from hipfire to any of the zooms or vehicle just gives the error "Too high sensitivity 1 - Maximum is 10".