Sadly, demoted from ☆☆☆ to ☆as of 7 July 2021. Starting ten days ago, the extension was unable to associate different logins to a domain with my different accounts: Google Drive was always personal, or always work. Since Independence Day, it's been trying to fix that by jumping frantically back and forth between different containers in the same tab - window jitters like crazy, and your only option is to close the tab. Today the jitter spreads to previously stable tabs when you close a schizophrenic one. The only solution: turn the extension off, and lose all the walls between different roles.
This is a great idea, and I hope the Mozilla team figures out how to make it WORK RELIABLY. Meanwhile, I'm going to be making a lot more use of Chrome personas.
When I gave this add-on a five-star rating, (see below) I didn't realize:
IF YOU TURN IT OFF, ALL YOUR SETTINGS GET WIPED OUT.
I had a couple of hundred URLs associated with my personal, work, coding, educational and Facebook IDs. To see if add-ons were making Firefox a memory hog, I turned them all off. When I reactivated Multi-Account Containers, the only associations that remained were with "Personal" and those were all wrongly linked to my coding persona.
So now I'm wondering if I want to take the trouble of rebuilding — at least a half day of work to undo what should never have happened. If Mozilla security protocol means an inactive add-on can't retain any data, there should have been a CONSPICUOUS WARNING of what I was erasing.
=========earlier review=========
If you are an admin — Google apps account, a Facebook page, whatever — you can finally sign is as a user/visitor at the same time you're editing, in side-by-side tabs in the same browser. And it's nice to have access to a persona not associated with any of your social media or email accounts, so you can escape tracking and junk email when you browse.
