I understand what each option sets for JVM application, but can’t tell why it’s counterintuitive for Android. For example: in JVM, a library sets targetComp = 17. A project consuming that library, using sourceComp = 11, will fail to run, due to a difference in binary format (different version compiled vs. lower version trying to use it). That’s understandable. But doing a similar experiment for Android works just fine. I created an app and set the sourceComp = 11. I created a module targetingComp = 17 and added it to the app as a dependency (aar). I expected this to fail, because .aar contains .java classes compiled against Java 17, while running the project with Java 11, but it’s running just fine. Am I missing something here?

If I understand you correctly, and I am not entirely sure what’s the status on android, but we know that google is backporting java features through desugaring and recently also shipping features to older android releases through google play (I forget the name now)

I think you mean project Mainline