Preparing a Mac for sale - How to securely delete the contents of an SSD?

Hi MPU folks!

I sticked to this Apple Support article when preparing my Mac for sale:

What to do before you sell your Mac

Will this procedure described in the article (formatting my SSD and installing macOS again) be enough to securely wipe my SSD or will it still be possible for data forensic experts to access the previous contents?

Previously I had FileVault activated on that SSD. Am I right to assume that even if someone could recover the files these would still be encrypted and therefore useless? Or am I missing something?

I appreciate any advice.

Good overview here:

Also, here’s a nice, free macOS security guide hosted on Github:

TLDR if your SSD is whole-disk encrypted, then as with IOS, folowing Apple’s instructions essentially re-encrypts the drive using a different key, then the OS obliterates all of the keys in Effaceable Storage, rendering all user
data on the device cryptographically inaccessible.