Backing up seed phrase safely

Of course, engraving it on a thick metal plate to protect it from physical destruction is an obvious step.

But what about protecting it against random person who could randomly (or deliberately) find it? It seems like it's not that secure to openly engrave seed phrase. Are there any standards regarding encrypting it anyhow, hiding/obfuscating? At least to have enough time to react to it if you detect that your storage has been tampered with.

What about online backups also? In a situation where all physical assets, including house itself, may be seized or even entering country may not be possible anymore is not just a distant theory but a real danger. In this case, only online backup could help. Are there best practices regarding storing them?