There are some nuggets of wisdom in this thread: http://www.airlinepilotforums.com/showthread.php?t=8148 . Riding SIC in a IISP would be exactly the same as riding SIC in a King Air 200. Look particularly at post #10 in that thread, I think that's the ticket.

I still think you'd want to get yourself as knowledgeable about the aircraft as possible, so that if asked in an interview situation about the experience, they might give you credit for it.