An existing pass through configuration is customized with the usePassThrough utility. The first parameter is the object to customize, the second parameter is the customizations and the final parameter is the behavior of merging. One of the example use cases is customizing existing unstyled themes like Tailwind.
The mergeSections defines whether the sections from the main configuration gets added and the mergeProps controls whether to override or merge the defined props. Defaults are true for mergeSections and false for mergeProps.