Tracking Protection was added in Firefox 42, so we should be able to turn on support for it.

The pref is currently disabled: https://github.com/citp/OpenWPM/blob/master/automation/DeployBrowsers/configure_firefox.py#L30-L35

However, enabling the pref still won't work correctly as we remove the update URL to prevent stray HTTP requests to mozilla's servers during a crawl (see: https://github.com/citp/OpenWPM/blob/master/automation/DeployBrowsers/configure_firefox.py#L137). It should be pretty easy to figure out the API to query and manually download the list at the start of a crawl.