The current version of the plugin
https://github.com/mel4tonin4/inline-serialization-plugin works as advertised. It is compiled against Kotlin 1.3.61, Meta 1.3.61-SNAPSHOT, and Serialization Runtime 0.14.0.
The big issues for me are: can I make the IDE aware of my plugin? Can I work with Kotlin 1.3.72 and Serialization Runtime 0.20.0? Where is Meta 1.3.70-SNAPSHOT?