You could split the key a few ways if you don't want to trust that one of your stores won't be compromised https://en.m.wikipedia.org/wiki/Shamir%27s_secret_sharing

Or, just apply some simple, easy to remember permutation to the key that no one would be likely to guess - eg rot13 the key, or add 1 to every character, move the first 14 characters of the key to the end of the key, etc.

> Particularly 1Password which I think is a pattern if I remember correctly.

What does that mean?

Probably that the key has features that allows 1Password (and potentially anyone) to recognize that its a 1Password key. E.g. Fixed size, patterns of spaces or dashes, specific digits, embedded error correction, etc.

Yeah that is what I mean.

Similar to how a lot of package companies have a certain pattern, length, whatever for their tracking numbers. If there was a somewhat reliable way to say "This is a 1Password key" or "This is an iCloud key" it makes it means even without context it could be an issue.