Sorry about the file size. We encountered quite a few issues with exporting from blender into godot, maybe it's just our inexperience, but it didn't feel very intuitive and we ended up having a ton of duplicated mesh data which ballooned our file size.
I wanted to have proper graphics settings so that people can improve their performance, but we spent so much time fighting against godot's model importing that I didn't have enough time to worry about it.