Did you consider using RectTransform for tiled/9-sliced sprites instead of having separate width / height fields?
Or maybe at least to copy those data from RectTransform when it’s added instead of normal Transform. That could be the first step in better interaction between UI and 2D 
Something to be considered down the road. We did consider it, but current focus was for 2D world building, faster layout options etc. Coupling the two adds some complexity in usage. Basically the idea was to bring the 9-Slice technique which is available and typically used in UI to 2D level building.