As Gradle 4.7 is out, there had to be an issue for this :) The documentation to handle this is [here](https://docs.gradle.org/4.7/userguide/java_plugin.html#sec:incremental_annotation_processing). I think auto-value-parcel could implement this? (but I might be wrong as I don't fully understand all the works behind annotation processors).
