Current Situation:

We have a 3D model in blender when exported to:

GLB (compressed) = 2.8MB
GLB (uncompressed) = 9.8MB
USDZ using Blender (default settings) = 24MB
USDZ using Reality Composer (uncompressed GLB as input) = 9.8MB
USDZ using Sketchfab (GLB or FBX as input) = 5.5MB

Problem:

We want to reduce the file size of USDZ to as much as possible keeping in mind the Sketchfab export as a benchmark. We don’t want to rely on Sketchfab since uploading, adding textures, tweaking materials, and exporting files is time-consuming using Sketchfab. We are planning on converting a few dozen models to USDZ in the near future.

Note that there are no textures in the above file at the moment.

Few questions

1. Any suggestions on what would be the best workflow to get an optimized USDZ?
2. Are there any settings that we should look into on the software side?
3. Are there any alternatives where we can batch process/convert the FBX or GLB files to USDZ?

Thanks in advance.