I'd be willing to bet the Chrysler mechanic won't know anymore about this car and the problem than the Ford guy. Here's what you need to do:

Since they are all clueless about this and won't pay attention to what you are telling them, talk them into replacing the entire supercharger, but make sure you let THEM come up with that diagnosis. It won't fix it, but it might make them feel better knowing that they knew more than you, and you will have a fresh S/C. Drive it for about 30 minutes and show them it is still acting up and then help THEM to decide it's the I/C pump. You'll be good to go for a long time !

RL