Link: https://live.dovetailgames.com/live/train-sim-world/articles/article/train-sim-world-june-studio-update
Wether their efforts are good enough can only be found out once we can make up our own trains and run them the way we want to test a lash-up of SD40's on trains of prototypical weight.
And then swap the SD's for GP's and AC4400's and load the train to adhesive limit. However, these locomotives still need to be done by DTG and will perhaps require completely new Scenarios and Services in a future comprehensive update to CSX:HH.