Yeah, the server already uses LetsEncrypt certs, and the forum has a special module I wrote that corrects all links and forms based on if you view via HTTP or HTTPS to retain backwards compatibility. Just update your bookmarks if you want to use SSL.
I know someone who shut down their site because it wasn't realistic to do exactly this - and the dumbtarded software it ran inserted absolute links to itself all over the place. Not upgradable, not fixable. It had some 7000 articles and stories, being dependent on search results to drive traffic, and without that it was demonetized and shutting it down was the only realistic option. (Actually, the assets were sold to a competitor, who bought it to shut it down, but decided to leave the material around as a reference, as its own property.
) The people who built that system weren't technical, and the site designer they hired had no idea about such technicalities. (It also had a million other stupid software issues, like occasionally running extremely complex cross-table queries against mysql, that couldn't be optimized; when this happened the whole site would stop and hang for a few seconds.) They couldn't really blame anyone for this, just all unfortunate, and not something the ideologues at google would think twice about killing off.