How do I create a new instance of a dependency, instead of using the existing singleton instance?

I’m trying to get all configurable options of a simple product by calling linkManagement->getChildren() in a plugin which runs after Magento\ConfigurableProduct\Block\Product\View\Type\Configurable.getJsonConfig(). The problem is that LinkManagement.getChildren() is only returning the configurable options that are not out-of-stock when it’s called within the product detail page. However, if I call it from the API via http://<my_site>/rest/V1/configurable-products/<sku>/children, it…