• Is there any tutorial about how I can create my own declarative implementation for my convention plugin? • The limitation about being able to use only one plugin is still there, right?

Hi. At the moment there are no tutorials for developers, and it's not the best time to adapt plugins given no compatibility guarantee at this stage . See https://gradle.github.io/declarative-gradle/docs/CONTRIBUTING/#adapting-gradle-plugins For the second question, I would rather leave it to the team. I cannot find documentation or a GitHub issue for that