Unclear how this quoted comment relates to what I was replying to (which was about exporting / backing up your credentials).

But I'll respond.

> Will I always be able to use any credential manager of my choice? Any naturally also includes software that I might have written myself. And would you be in support of an ecosystem where RPs might block my implementation based on my AAGUID?

If a website were to block your custom software's AAGUID for some reason, you can change your AAGUID.

AAGUIDs in the consumer passkey ecosystem are used to name your credential manager in account settings so you remember where you saved your passkey.