Christian, you didn't understand the issue. He and many others did exactly that no-www to www redirect like is recommended, but this script for some reason doesn't work on sites with www.domain.com , only works with clear domain.com. I had to make changes on 2 domains that I use the script and remove www redirects and setup in cloudflare and .htaccess to work without redirect to www just to be able to even see the clicks and customers. Even when people are adding the site www. is automatically removed, in javascript tracker file. You should give the option for www. and don't worry about how others will implement it, people know about possible duplicated content and redirects.
EDIT: I've found the issue, Cloudflare quirky setup. It works with www, too.

Hello Boris,

This feature won't probably be implemented too soon but I will keep the ticket open.

The reason why this isn't implemented is because from the user experience point of view acessing your site as domain.com OR www.domain.com should lead to exactly the same content. This is the recommended way to server your website content and you should redirect the non-www version of your site to the www version.

So, by not implementing this "www" support userTrack "forces" the webmasters to follow the best-practices in order for it to work properly.