Up to a maximum of 50 output coverages can be created using Split. The number of output coverages is determined by the number of unique values in the Split Item.
If more than 50 unique values exist within the Split Item, use Select to create temporary coverages that include subsets of your original data. Select's Expression parameter can be used to select groups of features with specific values to write them to a new coverage. These temporary coverages can then be used with Split to create the full complement of output split coverages.