Luke Dashjr on Nostr: Never use shred on a modern system. It is always ineffective, and in the case of SSDs ...

Never use shred on a modern system. It is always ineffective, and in the case of SSDs can damage them (not just wear, but fills the disk to the max).

If you don't mind an attacker knowing how much free space you have, ideally you should also enable discards in luksOpen (check out the persistent setting) and mount.