Which run mode takes the most time to perform machine learning tasks?

The correct answer is Local Auto. The uploaded answer was right, but its explanation was sloppy because it incorrectly described Local mode as the most time-consuming mode. In FortiSIEM machine learning, Local Auto mode selects the best algorithm by evaluating multiple candidate algorithms. The User Guide states that in Local Auto mode, “FortiSIEM picks the best algorithm” and that the Max Run Time parameter limits how long the job can run; longer runtime can produce better results. That is why Local Auto can take the most time. Forecasting and Regression are task types, not run modes.