Hi @andbale,
Thank you for your thread and for downloading the plugin. I am Andrea and I will help you in your request.
I confirm you that with the developed plugin I tried to make it more and more functional and simple, to answer your request: I confirm you that the referrer-policy: strict-origin-when-cross-origin header is set automatically by the plugin on your site and also the header.
For the header the X-XSS-Protection header was supported by early versions of the plugin, then over time some documentation changed and I removed that HTTP response header X-XSS-Protection was a feature of Internet Explorer, Chrome and Safari that prevented pages from loading when they detected cross-site scripting attacks.
The decision was made because of such descriptions that I want to provide for the sake of completeness of the thread.
Note:
This means that if you don’t need to support legacy browsers, we recommend that you use the Content-Security-Policy option that I have remaining part and even with the ability to customize values in the case of the more experienced.
I hope I have helped you and offered good assistance ??