@noahsmybro completely agree! great extension and have been trying to find an alternative for awhile, but it would be excellent if opera implemented this, or ported multi-account-containers to opera.
I did try this, and initially it does seem to work, Not as clean as extension for firefox. https://chrome.google.com/webstore/detail/sessionbox-free-multi-log/megbklhjamjbcafknkgmokldgolkdfig