EXT_mesh_gpu_instancing not supported in transcoder

Hi, I have a glb file utilizing the EXT_mesh_gpu_instancing and EXT_instance_features extensions

See
https://github.com/KhronosGroup/glTF/blob/main/extensions/2.0/Vendor/EXT_mesh_gpu_instancing/README.md

The draco_transcoder.exe ignores these extensions and my instanced objects disappear.

I see some code fragment around the EXT_mesh_gpu_instancing extension, but my guess is that the loader hasnt implemented it.

Is there a branch working on this feature or anything?

Thanks,
Arne