Office加载项旨在为Office解决方案进行跨平台开发.目前，它不支持限制平台.这是主机"元素的规范，用于指定Office主机应用程序供您参考:

The Office add-in is aim to cross-platform developing for the Office solution. At present, it doesn't support to limit platform. Here is the specification of "Host" element which used to specify the Office host application for your reference:

您可以在此处参考关于清单中指定主机的更多详细信息.而且，如果您希望Office加载项支持此功能，可以尝试在此处提交反馈.

You can refer to here about more detail of host specifying in the manifest. And if you want to the Office add-in to support this feature, you can try to submit the feedback here.