When using the "limited to designated sites" setting you have to wait for every tab to time out before you can add it to the container.
Also the possibility to use wildcards in the URLs would be a minimum requirement to make it usable for a developer.

Add-on is in Russian and it is NOT the language of my OS nor FF. I don't see the option to change the language. It doesn't spark confidence in this add-on in current geopolitical situation.

Terribad sync, messed up everything

впн тут нет

Common your synchronization are shit, i lost all my open default sites switching between Floorp and Firefox, in firefox lost all my custom containers and data (in floorp are ok, but cannot restore in firefox)

Completely breaks syncing between Android and desktop.

no sirve para multiples (distinats) cuentas, estilo multifox

"К сожалению Mozilla VPN в вашей стране недоступен". Базара ноль.

Не работает

My firefox is updated but still unable to add this extension.

Cet add-on indispensable n'est plus maintenu depuis 1 an et est bugué. Par exemple, je dois sans arrêt retirer des sites de la liste des sites gérés par un conteneur car ils reviennent toujours. Ça rend l'identification problématique si un IDP (comme Facebook login ou Google login) se trouve réassocié sans arrêt à un conteneur.

This essential add-on is unmaintained for one year has some anoying bugs. For instance, I'm forced to remove the same website from a container managed website list again an again because it get reassociated again and again.
This cause IDP (like Facebook login or Google login) to fail everytime if their website is reassociated with a specific container. (SSO breaker)

Despite having the "Select a container for each new tab" box checked When you open a new tab, nothing happens. Not even contextual dialogue is activated. I have the extension installed and enabled, but I can't get it to work in Windows 10, not so in Linux Mint, which goes without problems.

no wildcard,no manual edit feature，looping on onedrive.live.com and login.live.com