Well an air force C130 requires a Loadmaster at all times. A flight safety issue as who would perform the vital monitoring that is required.
As a L100 is only slightly modified from a C130 it could be a real issue, as you could bleed to death or have fire overheat problems with out the normal in flight checks, if you think that the loadmaster is just for when you are carrying cargo and Pax you are way off the mark. Need emergency extension of flaps and landing gear who is going to do it. A fire who will attend to that um I could go on.
The flight deck crew would be too busy with controling the airplane and systems
The armed forces have the rule you can leave the navigator if carried behind but not the LM.
The LM is the best preventative in surance policy you could have, and would be able to handle anything that goes wrong aft of station 245.
Regards
Col