Yes they can be useful. Construction Worker Mode attacks people not wearing hard hats.
Law enforcement mode attacks people with their weapons drawn so if you holster yours it should leave you alone.
The subway Stewart is bugged so it is almost impossible to give the token over you have a window of less then a second.
The medical one is mostly passive it wont actually heal you but is harmless as long as you leave it alone it will go up and shock hostiles though. That is about all I can think of regarding them