Looks like the conversion from prefab to scene is not working, the mesh are not imported.

[Gobi-one]

Other than that, the textures, materials are imported correctly.
Here is the stack trace of one of the 10.000+ exceptions I have when trying to import the Polygon prototype pack https://syntystore.com/products/polygon-prototype-pack:

E 0:01:21:0851 asset_base.gd:77 @ load_binary(): Asset::LoadBinary::PackageExtractBinaryFailed
<C++ Source> ./core/variant/variant_utility.cpp:905 @ push_error()
asset_base.gd:77 @ load_binary()
comp_doc.gd:416 @ _comp_doc_mesh_filter__mesh_from_ref__gltf_scene()
comp_doc.gd:256 @ _comp_doc_mesh_filter__mesh_from_ref()
comp_doc.gd:611 @ _apply_component__mesh_filter()
comp_doc.gd:450 @ apply_component()
comp_doc.gd:515 @ _apply_component__game_object()
comp_doc.gd:446 @ apply_component()
comp_doc.gd:57 @ comp_doc_transform()
comp_doc.gd:21 @ comp_doc_scene()
asset.gd:139 @ asset_native_format_importer_prefab()
asset.gd:18 @ asset_scene()
upackgd.gd:118 @ ()
upackgd.gd:129 @ ()
upackgd.gd:196 @ build_all_prefabs()
browser.gd:90 @ load_package()
browser.gd:45 @ ()

I use the last versions of the libraries and GODOT 4.1.
Don't hesitate to ask for more infos if needed.