Better than keys-below-wallet is keys-inside-wallet. I acquired a second wallet-like thing (just looked it up now, it looks like this kind of thing is usually sold as a “phone pouch”), in which I put my keys, a couple access card for electronic locks, and a library card. It sits flat in my back pocket and is generally noticeable when and only when I think about it.
Better than keys-below-wallet is keys-inside-wallet. I acquired a second wallet-like thing (just looked it up now, it looks like this kind of thing is usually sold as a “phone pouch”), in which I put my keys, a couple access card for electronic locks, and a library card. It sits flat in my back pocket and is generally noticeable when and only when I think about it.