Some extension relay on hard coded paths that are not exposed by vscode. See for example code-sittings-sync. Those extension are broken in the insiders version. I see t two possible ways:

1. Just expose all paths used by vscode to extensions. Otherwise they will hard code them. No more security, just more messy code.
2. Expose if the extension is used by the insider version. There might be a way, but I have not found it yet. I thought about getting the version and check if it ends with -insiders, but I have not found a way to get this information either.