Question Regarding Google Android Backup Encryption

Thank you for the link. Unfortunately, I haven’t had good luck with the Google Help Communities in the past. Since it’s entirely volunteer-run, the answers often lean toward generic or automated responses rather than the deep technical insights required for security questions.

Either way, I believe this is an important question for the privacy community to have a definitive answer to: When backup is enabled in Android settings, what exactly is sent to Google’s servers and genuinely protected by client-side encryption (via screen lock)? Specifically, are the media attachments (files, videos, and photos) sent and received in RCS messages protected by this client-side encryption during the backup process?

If anyone is able to get a solid, sourced answer to this question, I will donate $20.00 to Privacy Guides and post proof of my donation in this thread as a thank you for the help.