It would like to create a very simple theme editor, with very high level control (limited customization). I would like to generate a uxml from the entire hierarchy from a VisualElement root, like the UI Builder works (load a file, change it, and save again to uxml). I took a look in the UI Builder source code to understand how to serialize/deserialize the uxml template into a VisualElement or VisualAssetTree, but there is a lot of Unity internal code, not exposed. If there is a way to implement this that i'm not seeing, it would be very nice to know! Thanks!