nostr:nprofile1qy2hwumn8ghj7un9d3shjtnyv9kh2uewd9hj7qghwaehxw309aex2mrp0yh8qunfd4skctnwv46z7qg6waehxw309aexjcn09ejh2tnwdaehgunfvyhxzurs9uqzp5daxvenwv7ucsglpm5f8vuts530cr0zylllgkwejpzvak0x2kqmehusjv has support for it. You can across the app block any user. There is also a generic Lists editor, which is more advanced, but it gives you full editing of your lists, including the mute list.
In settings, you can remove accounts you have muted. Maybe I'll add an option there to edit the list in a user friendly manner.