Nowadays we have more “hooks” into Bob.jar, that allows for a custom .jar file to add functionality to it.
These .jar files are loaded if they’re located in the correct extension folder : /plugins/share
example from spine
(source for that jar file is found here, and the build script is found here)
The .jar file is loaded by Project.java here.
I think one option would be to add a custom step to the AndroidBundler, that allows for running a custom tool on the package folder.
One major drawback for this setup is that the user would have to have the required tools installed (e,g, gradle and potential SDKS), unless the extension can bring those files.
I’d prefer if the extension’s plugin would contain any tools needed.