I installed and tested on a local Xampp system and a Linux/Apache Webserver. Php versions 5.3 / 5.2. It is a little bit hard to test and to 100% confirm. How look for something that's not there.
Tested for 2 cookies and 1 local storage (Beez template fontsize). None was sent to the browser before clicking the accept button. i.e. I didn't have to confirm the cookies by the browser. I tested with Firefox with confirming single cookies activated.
1. The sessioncookie was omitted.
3. Beez font-size changer didn't work when changing pages. As expected. This one is set by the template and started before other extension.
After clicking the accept-button I got 3 cookies.
1. A cookie from the extension.
2. The session cookie.
3. The language cookie
and 4. The Beez font-size changer worked.
If you use Google Analytics the developer has a free plug in for it. I did not test this but assume it works fine together with his own cookie protection.
I contacted the developer and he promised to add a "regret" functionality with, if possible, deletion of the already set cookies.