New companion weapon: flamethrower.
Packmule module: allows the companion to hold more.
Distractor module: causes more “aggression” or focus from enemies onto the companion. Possibly even allow it to have improved resistances but lowered damage with it on.
Hacker modules: chance on dealing damage to hack the target, different chance dependent on the weapon (rocket having highest and machine gun and shotgun having similar rates).
EMP module: chance on hit to disable the target temporarily, chance dependent on weapon.