Earlier quoted context omitted.
If you haven't already, change your user agent to get it down further.
You have to stick with known popular user agents. To mitigate tracking by UA you need a randomized user agent that changes periodically. Panopticlick won't be able to account for that in its stats. It's not a good idea to switch UA on every request since it will be hard to diagnose breakage caused by a site that rejects particular UAs.
"Periodically changing user agent" sounds pretty unique if you ask me. Especially if the extension isn't super-clever and changes the user agent for accesses that happen on the same page.
And the fingerprinter could be super clever and look for features that your purported browser isn't supposed to support... And if your browser does support them, that's a strong identifier.