Possible, but not recommended. SGDEX manages the Video node for you. If you were to start interacting with it directly, the results could be unpredictable.

With a custom view like the one you link to, there shouldn't be much need to access the Video node directly. You can access any field on the Video node using the "Proxy Node" mechanism described in this doc: https://github.com/rokudev/SceneGraphDeveloperExtensions/blob/master/documentation/6-ContentManager_with_Custom_Views_Guide.md

If you have a use case that isn't covered by that, we can take a look at how better to support it in the future.