There is a way to manually embed the VCS of a Sound in the Sound editor: select the Sound, then from the Action menu, select Add VCS layout.
To protect your work, the default case is to embed whenever you make a change to the range, widget types, layout, or presets. The idea behind automatic embedding is to prevent people from losing changes. It's based on the assumption that it is easier for you, as an expert user, to intentionally remove all embedding at the end (Action menu with shift-key held down, choose Remove VCS layout) than it would be for a new user to figure out why they might lose presets or the layout organization when they combine two existing Sounds from the library.