To use on Omniverse Audio2face, you must export as USDa and make a change at the begginig of the file exported.
metersPerUnit should be equal to 0.01
metersPerUnit = 0.01
reference with the explanation of the fix
Tutorial from Nvidia showing how to do the process inside Audio2face
You can follow the instructions until 11h20, where he exports the mc and xml file.
after that you can follow this video to import the face animation to blender.
Here, in Patreon you can download all the files to test yourself how the import works
Free download of the addon
https://gumroad.com/l/mocap_import
The source files
https://github.com/carlosedubarreto/b3d_mocap_import