Must-Use Plugin

Paul, you might be interested in this post about Installing a WordPress mu-plugin automatically

In the post, the author explains how they created a function allowing users to press a button to copy the “must-use” php file into the “/mu-plugins/” directory. Maybe your plugin should run some kind of code that would, on installation, move the current code into the “/mu-plugins/” directory and on uninstallation, remove the code (standard cleanup).

https://www.ads-software.com/plugins/cloudflare-flexible-ssl/