I would like to suggest to integrate a way to switch all sites to HTTPS easily from a WPMUDEV plugin so the need of installing RealSimpleSSL gets obsolete as it isn't capable to handle HSTS requests without very expensive additional costs.
I think it would be in the interest of all members if HTTPS and HSTS could be handled with a plugin we have already installed in WPMUDEV.
For that purpose Defender (Security)
Hummingbird (Speed - Optimization) would be the ideal place to get things done.
To get things done it could be built on the already existing version of RealySimpleSSL and extending it so that HSTS requests can be enabled on a site by site or network-wide setting.
A place to manage all settings centralized would be nice too - the ideal place for that would be probably the WPMUDEV Dashboard, where also a way to handle the cookies could get integrated.
All you need to do to enable HSTS is add a header to your site's .htaccess file. Web browsers recognize this header, and then take care of the rest without any further intervention on your part.
copy the following into the header of the .htaccess file
Header set Strict-Transport-Security "max-age=31536000" env=HTTPS
This solution could get displayed like the multisite displays its options how to add it to the .htaccess but much better would be if there would be a way not only to influence the max age but also that it gets added via the plugin.
(In this case, max-age is set to 31,536,000 seconds, or one year) In Cloudflare yo can set certificates for up to 15 years so the max-age could be adjusted (multiplied accordingly)
It really does not make much sense to charge multisite customers for that "simple addition 200$". See WPMUDEV as an alliance against the very common and typical WordPress RipOffs!
Therefore much better would be to integrate Really Simple SSL into one of the WPMUDEV plugins and adding that options. Also for the other mentioned things are solutions quite easy to achieve.