Misleading quote from PPRuNe Towers:
"Do it with people who have actual flown two crew. Most courses are actually the blind (but confident and taking your money) leading the blind.
Rob"
You have to have a minimum of 500 hours multi-pilot (NOT dual) before you can become an MCCI. So, the chnaces of doing an MCC course with instructors who have NOT flown multi crew is precisely.......NIL. 0%. None.
By all means investigate the backgrounds of the instructors as much as you can - but they will ALL have at least 500 multi-pilot hours behind them.