I know it's a question, but not one that needs an answer. Such a group could post and share code samples, challenge each other to API competitions, and generally grow the knowledge of everyone. I'd love it if points were awarded for contributing working code in various programming languages. Canvas could host weekly challenges focusing attention on specific problems. An example challenge I posted on a different forum
Challenge: Use the API to create a list of all students who have not submitted one or more assignment.
Solve this problem, tag it with the language used, and before long you will have amassed a huge cookbook of recipes to solve everyday coding situations faced when developing against Canvas.