Good stuff. However, I have caching of HTTPS pages disabled (which makes no discernible difference to page load times on my modest 36Mbit broadband), and I also enforce HTTPS (only occasionally making an exception when absolutely necessary), so this won't make too much difference to me. I re-iterate my call for HTTPS on every website, and I await the inexplicable downvoting from those who seem to think it's a bad idea because its hard work* or something.
*Before anyone says LetsEncrypt is difficult to understand etc., I will note that I find it utterly seamless with my hosting provider. In any case, that's not an argument against HTTPS, it's an argument for simpler implementation of HTTPS certificate management.