This is very useful. But the project I’ve been working on for long, uses the same VS version, same VS packages, and didn’t have the feature (there is asset reference to the script):
Is that because my project too big, so Unity turned it off? Anyway, how do I turn it on?
This is not something you can control for now. Depending on how many prefab/scene/meta files you have in your project and the projected memory needed to properly index all of this, Visual Studio will automatically enable or disable this feature.