If it times out it is either inefficient, either it gets lost in an infinite loop in some cases. Nobody can know, you don't provide any information. Please refer to the documentation: https://docs.codewars.com/training/troubleshooting/

No.

Multithreading reduces your runtime by a constant factor ( the number of threads ); you probably need to go from O(n²) to O(n log n).

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From the Kata description.

rotors // array of array-of-rotor-values. Each array-of-rotor-values is applied to the corresponding display line

Not a suggestion.