There are strings in Python already that reference classes: type annotations. PyCharm knows how to populate, warn, and navigate to the "interior" types there
I can't think of any reason why it couldn't be taught to behave similarly for a config file. You can do it today field by field via language injection but if there are a lot of them then I think the config file would need a JSON Schema with the x-intellij-language annotations on the relevant fields https://sourcegraph.com/github.com/JetBrains/intellij-commun...