My experience with shunt trip breakers had to do with commercial kitchens. Like you mentioned you tie the shunt trip breaker in with the FA supression system. I have done a couple systems now. One system speced the entire panel for that area be shunted. Of course the lights and other emergency items were fed from another panel. Another system had me shunt certain items throughout the kitchen. They basically spec that anything under the hood being suppressed be shut down. Another instance of shunting is for elevator recall during a fire alarm. The distribution panel supplying the motors for the affected elevators are shunted. Of course the cab lights are fed from another source.
