combi operation

Can we change the size of cargo area on main deck on combis (like 747-400M, MD11 Combi)?  i think they can be actually changed in the real life.

Nope, neither in real life nor in AirlineSim this can be done in short time. There are some QC variants available to have it as passenger aircraft or cargo aircraft.

I think you can at least change the size of cargo area for long time operation. Boeing states that you can either put 6 or 12 or 18 pallets with different mount of passengers in each kind of configuration on 747-200C.

http://www.boeing.com/assets/pdf/commercial/airports/acaps/747_123sp.pdf

That's exactly what i want. i have no intention to change the size of area each time it operates a flight. i just want to have a more cargo or passengers configuration in general.

Is there any choice it will be added ingame?