The only thing I would love to see for containers is some sort of VPN that lets you connect through a different server on a specific container, and potentially isolated web history between containers. Then if I'm live streaming my browser to online strangers, one of the suggestions should be for anything personal (or if streaming to relatives / co-workers you don't expose your online life, which can be problematic to some), and also due to the container going through a VPN, or maybe even some sort of paid proxy service idk, my IP isn't potentially exposed to internet strangers. Given such an expansion to containers, I would double down and if you open any link from another app, Firefox would ask you which container to open the link through, this way you don't open it under the wrong container.

I know, I know, probably a bit more than containers were intended for, but the containers thus far have been great otherwise. No need to open multiple browsers to test software quickly under multiple accounts, I can just login through all accounts I need to test on multiple containers.

Edit: The more I think about it, the more I feel as though Mozilla could find plenty of VPN (their own underlying provider included) providers to fund support for these changes to make them generic across VPN services and transparent.