This page is dedicated to providing the answer to the most asked questions about the plugins.
- VSCode extension - Minecraft bedrock
The plugin is built around the idea of supporting marketplace-ready content. Therefore, it avoids experimental/beta/undocumented features unless vanilla files have been seen implementing it.
This thought should avoid situations where everyone starts using features. Minecraft either then fixes it or removes it, which causes developers longer developing times or discarding content. It also goes that supporting experimental increases the workload of maintaining schemas by a lot.
If it should be supported then go ahead and make an issue on the github repo
You can ensure the plugin is activated by checking this article