Yes. You don't have a profile on Amethyst or Damus - you have it on Nostr. Your data is stored in the relays & not clients like Amethyst. So you can switch or even use them simultaneously

Amethyst is a client damus is just a another if you have your private key you can transfer everything over

Your user profile is on Nostr Damus and Amethyst are Clients a few of many that run Nostr your profile works on all of them