The module you export and import will indeed be added to the appstore modules. You can off course give it another name.
But…why would you want to do this. The best practice is to leave the appstore module as is, so you can update it to newer versions later. You create your customizations in an extension module using as much as possible from the appstore module in a way that allows you to update the appstore module without loosing your functionality in the extension module.
You could always contribute to the development of the appstore module by providing feedback in the appstore or in some case by cocreting it via github.