Unable to cycle timesteps with python on a decomposed case

Hi everyone, I have a 140GB transient LES case of my FS Team to post process and i made some python scripts to print slices of the car in various places trough time.
I am not able to cycle timesteps without reconstructing the case, and for what i know decomposed cases are faster to process since they work with multithreading (I have a Xeon E5 2620 v3).
Please correct me if I said something wrong since I’m not 100% sure about multithreading and its implications on processing times.

Any help is appreciated, thank you.