Hi, I am an engineering manager in charge of UI Toolkit.
You are right that UI Toolkit lack certain features and does not come with a comprehensive performance-oriented documentation for Runtime UI. This is because it is still in development and only offered as an alternative to uGUI.
Regarding your questions about what can be changed or added later:
- Providing custom shading capabilities is on our radar, although we intend to review exactly the best way to do this. It may or may not be through custom materials.
- World Space UI is definitely a feature we intend to add, it is very high on the priority list
- string-based references / UQuery are here to stay but we intend to make experience closer to what you get in Unity with references that can be dragged around and don’t break when the source object is renamed.
- Data binding for Runtime was just introduced and makes it friendlier to manage property paths.
Regarding the performance profile of UI Toolkit, we consider that baseline comparisons to UGUI and performance guidelines and tips are a must-have to be able to make UI Toolkit the default, recommended UI system for Unity. We’re also mindful of the specifics of different types of platforms, especially mobile, and intend to reflect this in the documentation.
In the next few months we will more than likely publish a roadmap update to state our current priorities, similar to what we have done end of last year. You can keep on eye on the UI Toolkit forum to follow along.