XGBoost MLeap bundle speed

Hi, I have the question below from another repo that I think is no longer active, so I pasted it. Basically, I don't quite understand why with bigger data batch sizes MLeap XGBoost bundle seems to be running faster. I assume it is threading but unsure. Please let me know that and if I can turn off such optimizations, I am trying to compare with something that's unoptimized currently.