黄先生是对的只有目前修改头才支持修改请求头。不过，我正在考虑支持未来版本的响应标头。

Does anyone know if Firefox extensions are allowed to modify HTTP response headers? For example, can an extension remove the x-frame-options header to let the page load in an iframe?

Thanks

S. Wong is correct. Modify Headers supports modification of request headers only at present. However, I am looking at supporting response headers for a future version.