Tooltitude for Go could act not only as a productivity extension, but as a language server which provides basic LSP functionality such as code completion, parameter hints, navigation, and finding references. We use it internally to debug code when it doesn't behave as expected. It could also be used in a resource constrained environment to try to save resources. I.e. run Tooltitude instead of Tooltitude + gopls.
This mode is activated only if the official Go extension is disabled. It's possible to disable it either globally or on a per-workspace basis. Then, reload the editor to activate the mode.

To turn it off, enables the official go extension back.

This is an experimental mode, and it doesn't support as many features as gopls does. So, if you have enough resources to run both Tooltitude and the official Go extension, we don't recommend using it.
You could report bugs or request features here.