The "full load" will be satisfied for any cargo type.
Configuration file: fullloadany
Command line: -F
Basically fixing the same problem as the train refit option does, this makes full load behave a bit differently. Instead of waiting for every car to be full, now if there's any type of cargo that's full will mean that the train leaves the station.
So, if you have a train that transports passengers, mail and valuables, you can set it to full load and it will leave when any of those reach their maximum capacities. This also works for planes, so that they leave when either mail or passenger compartments are full.
However, it is no longer possible to enforce a complete full load for mixed cargo trains.