Regarding multi account containers in firefox, it's possible to assign a site to always open in "whatever container", but it's currently impossible to do this for the "Default Container". The workaround is to either copy the current URL and open a new tab, or to use the extension to "Reopen this site in..." > "Default Container".
But it'd be nice to add support to autmatically open a given site in the "Default Container". For example, I want this for GitHub, often I get to a link via Google (which I have as its own container), and want to instead see the site in the default container.
Link to repo for reference: https://github.com/mozilla/multi-account-containers
