According to the Adobe Commerce documentation, the correct approach to change the stopwords directory inside a custom module is to use dependency injection to override the default values of the stopwordsDirectory and stopwordsModule parameters of the MagentoElasticsearchSearchAdapterQueryPreprocessorStopwords class. The stopwordsDirectory parameter specifies the relative path of the stopwords directory from the module directory, while the stopwordsModule parameter specifies the name of the module that contains the stopwords directory. By adding these parameters to the di.xml file of the custom module, the Architect can change the location of the stopwords files without modifying the core code or database.

To change the directory from your module

Configure Elasticsearch stopwords