I have used this custom MaterialXPreviewSurface with golden color (hex: #ffe29b), metallic 1.0, roughness 0.1 and the attached normal texture file:

I received the following answer from Apple-Feedback. Reality Converter currently does not support MaterialX in USDZ files. Here is a page detailing our current feature support: https://developer.apple.com/documentation/realitykit/validating-usd-files While Blender supports USDZ files, it currently does not support MaterialX. This potentially new Blender feature is being tracked here: https://projects.blender.org/blender/blender/issues/100894. Currently with Reality Composer Pro, in order for an export to USDZ to include all necessary references (including textures), one must make use of an RCP project, rather than just open up a standalone USDA file. The latter will result in the exporting of a USDZ with only a USDC inside of it.

Same here. No way to provide proper screenshots for a visionOS app AppStore Connect release. Feedback ID: FB13550735

After deleting all files in ~/Library/DeveloperXcode/DerivedData/ everything works as expected for me.