Hello! Latest testing build do contain Native template. Plugins don't have anything different in them. You can copy over without any problems, add gradle projects, or include Jars/aars.
It would be interesting to know what changes exactly you're struggling to migrate. We don't have a migration guide yet, but your experience and problems could help write one. I spent too much time writing new build system to question how to move to it, so I have quite a blind spot in what isn't clear in new build system. Please, feel free to
join Slack and ask your migration questions there, or do it here. We'll figure it out together and I'll write a guide based on our experience.
But basics should be same: you copy over the template App, put your plugin code into plugin/src/main/java, manifest entries into plugin/src/main/AndroidManifest.xml.
Project lives in Corona directory. New thing - there is a new gradle target: "setUpCoronaAppAndPlugins". Run it, and it will download and set up all plugins you have in your project, generate AndroidManifest.xml for the plugins and basically do the same as building a biuld with Corona Simulator (note, re-running it will overwrite adnroidManifest.xml). Press then select "Run" target, press "Run" (play button), and start your app in Android Simulator or Real device.
Note, that "setUpCoronaAppAndPlugins" will basically set up project from your Corona project, including all plugins and build.settings. After that, modify it, do whatever you want.
EDIT: I thought about it, and instead of using Slack, post your questions here. It's easier to answer them here and they'll be searchable for everyone.