Sorry, don't get the last part. You have exactly one AppleID as login, which may have further aliases. Depending on your initial account setup it may be any domain or an iCloud login. I have my regular custom domain email address for logins on Google, iCloud, Microsoft. All of them provide the possibility to create accounts without their own domain suffix. But once created, it can not be changed anymore (except of Microsoft).Right? I would hope that I could settle with my custom Apple domain and the take off my @icloud.com from My Apple ID because it’s being stuck to my profile along with my @gmail.com, imagine have 3 when costumes domains come out… no thanks