In the default settings the canvas fingerprint is changed on every page reload (you can test that on http://kkapsner.github.io/CanvasBlocker/test/test.html). Yes - this makes the fingerprint unique but since it is not constant you cannot be tracked.

If you want further information/discussion please open an issue on https://github.com/kkapsner/CanvasBlocker/issues where we can communicate nmuch easier.

PS: similar issue on github: https://github.com/kkapsner/CanvasBlocker/issues/154