[ME] DefaultValue does not work for textures in zipmods

[zmodpix]

For textures a default value can be set from the manifest via DefaultValue and DefaultValueAssetBundle parameters according to the documentation, however it does not work in the tested latest v266/3.13.4 version in KK.
In the code this is managed by LoadShaderDefaultTexture(), which calls AssetBundle.LoadFromFile() which - I think - only works with direct filepaths to .unity3d files, and it will fail silently if the asset bundle is not found (and it will always fail if the bundle is stored in a zipmod). Extracting the asset bundle and referencing the file directly from the manifest was a working, but not a comfortable workaround.
Is there any way to pull out default textures from zipmods directly?