The fact is, it’s not easy to guess a seed phrase. In fact, I don't think it can even be guessed. So, even if someone sees where you wrote down two or more seed phrases, it can't really cause any harm. But the best approach is this: don’t write it down somewhere people can easily notice. The seed phrase should be so well hidden that nobody can find it except you, or the person you choose to tell.As for me, where my seed phrase is hidden, it's very hard for someone to notice the spot. But honestly, I haven't been able to engrave it on metal yet. I have written it on paper, but it's still hidden inside a waterproof container. Still, the best way is for someone to engrave their seed phrase on metal.