ProGuard apk security

I want to make sure i understand. Is ProGuard automatically invoked in Build APK?

ProGuard appears to be among the top choices for making APK reverse engineering effectively impossible. is that correct?

Thank you

App Inventor does not support proguarding the final APK. Some extension authors will proguard their individual extensions, but it is not a feature that we support. You may want to look at one of the many App Inventor clones aimed at professional development, which tend to provide this additional level of obfuscation.