Hi wpigoury,
the Studio Text search looks up at the key / values pair that are defined in the platform. If a component is using hardcoded text - then the tool will not be able to find that.
If you need the ability of controlling the text in the custom components via the text editor, you can always build custom components that are using the text freemarker context object and create a custom text key that you can then render within the component as suggested in the example TKB article. In this way, you won't have hardcoded text in the customizations.
Hope this helps,