The ability to configure browser and extension settings differently for different profiles, plus different history/cookie for each. This is nice for experiment

The ability to configure browser and extension settings differently for different profiles, plus different history/cookie for each. This is nice for experimenting with changes to umatrix settings without having results "pollute" my long-lived container storage. Also nice as a relief valve for when I don't won't to deal with my locked-down default settings, and just want to open up a site with everything enabled in a temporary container that gets blown away when I'm done.