The VS Code Language Server currently relies on the connected InterSystems server for most intelloisense. For people who work client-side and either work without an active server connection or don't sync their local files with the server often, the Language Server should index the local client-side InterSystems files in their VS Code workspace folders and use that index for intellisense before consuling the server.
Thank you for submitting the idea. The status has been changed to "future consideration".
Stay tuned!