Apple is not going to support Web Components (Shadow DOM) as well. FF is working on it and even MS has "under consideration" status. Even if there were some

Apple is not going to support Web Components (Shadow DOM) as well. FF is working on it and even MS has "under consideration" status. Even if there were some issues with driving Shadow DOM standardization by Google I suspect that not supporting it by Apple is more defending iOS walled garden than real tech issues with specs.