Include policies.json for additional protection
You could add TorBrowser/distribution/policies.json for better privacy.
...
"DisableBuiltinPDFViewer": true,
"DisableFeedbackCommands": true,
"DisableFirefoxAccounts": true,
"DisableFirefoxScreenshots": true,
"DisableFirefoxStudies": true,
"DisableFormHistory": true,
"DisableMasterPasswordCreation": true,
"DisablePocket": true,
...
If you add policies.json Tor Browser will read it.