No, the cache is keyed by url (https://tracker.example.com/tracker.js https://tracker.example.com/tracker.js vs https://tracker.example.org/tracker.js https://t

No, the cache is keyed by url (https://tracker.example.com/tracker.js https://tracker.example.com/tracker.js vs https://tracker.example.org/tracker.js https://tracker.example.org/tracker.js) and not by IP. So those resources will have separate cache entries with separate ETag/Last-Modified/etc values.