One thing I forgot last time, AMS and L-AMS tend to be classified as equipment not weapons and thus would not be effected by carrying a hand held weapon
I don't think that logic holds up to scrutiny. Anti-missile systems are still basically specialized machine guns (or small pulse lasers, respectively) that need to be able to actively
shoot down incoming missiles in order to have any effect; thus, if there's something in the way that would interfere with the normal operation of the "standard" versions of the respective weapon, it ought to do the same for the AMS.
Could always head- or leg-mount one, of course. Handheld weapons only specifically prevent you from using arm- or torso-mounted weapons while you carry them, after all.