Then you can remove the key from amethyst and just use Amber as a signer for all apps.
How do I set up amethyst to use amber as a signer? I don't see an option for that in Settings
Figured it out, testing it now. I downloaded amber and set that up, then logged out of my account on amethyst. Then on the login screen there was an option to log in with amber. So far it works great!