These are good questions @tog!
Usually, our developers have a very concrete concept of how our code should look like. And, of course, we argue that by saying: “We want good code quality!”
In consequence, it’s very difficult for us to review and for contributors to participate in the development of (new) official plugins. For us, because we have these requirements internally and have limited time for reviews. For our contributors, because the mindset behind our requirements is difficult to catch if you’re not working all day long on Checkmk code.
Long story, short: I think, it’s a very good idea that community members work on a shared project. Either a mssql plugin for all platforms or an additional plugin just for Linux. And this energy and contribution should be independently of the official development. Let other users take part of your knowledge. Because, agent and check plugins are the most efficient way to share knowledge in the community.