SKevo Looking at https://discuss.flarum.org/d/22642-security-roadmap, seems that these tokens are deleted after 24 hours.
Assuming you have programmatic access to the FreeFlarum databases, you could set up a basic Django app or something that would associate each FreeFlarum site with a unique token, and send those tokens out to users. When they visit the site with those tokens, it would add a password reset token to the applicable FreeFlarum database, and make that link available to the user.
Or to make it even simpler, have a throttled button that will generate a password reset token and send it in an email to the owner of the FreeFlarum forum.