-- To block extensions but allow themes, dictionaries, and language packs, use `"allowed_types": ["theme", "dictionary", "locale"]` in the default (`"*"` ) configuration. (`"locale"` corresponds to Firefox language packs.)
+- To block extensions but allow themes, dictionaries, and language packs, leave the default (`"*"` ) `installation_mode` as `"allowed"` and set `"allowed_types": ["theme", "dictionary", "locale"]`. (`"locale"` corresponds to Firefox language packs.)
+ **Do not set `"installation_mode": "blocked"` in this scenario**, because `allowed_types` is ignored when installation is blocked.