Regarding closed classes, the all-open plugin ( https://kotlinlang.org/docs/reference/compiler-plugins.html#all-open-compiler-plugin https://kotlinlang.org/docs

Regarding closed classes, the all-open plugin ( https://kotlinlang.org/docs/reference/compiler-plugins.html#all-open-compiler-plugin https://kotlinlang.org/docs/reference/compiler-plugins.html#... ) may be able to help somewhat, though you'll still need to add an annotation to your base classes.