I am super satisfied with the Containerise extension https://addons.mozilla.org/firefox/addon/containerise/) as alternative for Multi-Account Containers. It lets you map whole classes of domains to unique containers, which is an awesome and robust solution for logins involving a lot of redirects. Here are some example mappings which also catch all real subdomains (but not "fakeamazon.com"):
@^(.+\.|)amazon\.(de|com) , Amazon
@^(.+\.|)spotify\.(de|com) , Spotify