I love the Account Containers and use them a lot. Since Firefox 91 there is also the option to enabled Windows SSO for Microsoft, work and school accounts. This is great, because I don't have to log into my work account every time.
But I do have a specific Account Container for Work stuff. But I get the option to sign into my Work account in every Account Container. This is not ideal. My idea is that the Windows SSO setting can be applied on a per Account Container basis. This way I can enable Widows SSO for my Work Account Container. And have it disabled for my other containers.