Different Aicraft types should have different trainings. Even same aircraft but in different operators may have different configulations. The concept is same but still some variations by each operator. Airlines may offer the load controller the dedicated local control training, or which called weight and balance training.
i.e B744F, some airlines can use the increased ZFW but others not.
Thus, you have to pass different trainings by operators and then you can work for them.
Cheers/Fire