I got a new external SSD drive to use as a Time Machine on my new MacBook Air M1.
I formatted that new SSD with a single partition on the format of APFS Encrypted, and assigned a password.
I went to System Preferences > Time Machine in macOS Monterey 12.4. In the file picker to choose a drive, at the bottom of the dialog is a checkbox reading
Encrypt backups, turned on by default.
👉 Is this encryption option within Time Machine redundant as I already have the APFS file system encrypted?
Is having both APFS encrypted and Time Machine encrypted harmless but costing in performance as everything is being encrypted twice?
What is the recommended configuration, APFS not-encrypted with Time Machine option "Encrypt backups" enabled?
Apple provides the support page, Keep your Time Machine backup disk for Mac secure. But it does not exactly address my question.