Depends....Some so called multi crew is simply window dressing to meet client or insurance requirements. The pilot in the RHS in these operations reads checklists, entertains the pax with briefings, talks when allowed on the radio, cleans the cabin and if lucky flies empty sectors. Often the pilot in the LHS seat has no idea how true multi crew works. Aeromedical in a light jet may be OK, but fish spotting? Hmmm.....
But it would seem that CASA is willing to assess every application on its merits. If your organisation has properly documented training, checking and procedures with all the human factors and CRM stuff that they want, and hopefully a policy of sharing the flying, you should have no problems.
Although I am guilty as charged when it comes to CASA bashing, I have to say that the three CASA FOIs that I had dealings with setting up ATPL testing have been most reasonable and interestingly, they were all very much on the same page with policy interpretation.
Credit where it's due - CASA listened and acted on this one. The only people who may be pissed off now will be certain purveyors of MCC courses and anyone who paid big bucks for one of their courses when they did not need to.