As discussed in https://github.com/kkapsner/CanvasBlocker/issues/438:

The access to the privacy setting is needed to display the notice for privacy.resistFingerprinting. So it's not that important but unfortunately I cannot make it optional.

CB only reads that and does not write any privacy settings: https://github.com/kkapsner/CanvasBlocker/search?q=%22browser.privacy%22&unscoped_q=%22browser.privacy%22