After yesterday spending ages deleting TMP containers, today I synced a new install of Firefox on a different, new PC. All TMP containers were recreated. Terrible.
Downgraded from 4 to 1 stars.

A week later I have just deleted all the TMP containers 'synced' to my new machine.
Switched off sync in add-on settings. Closed and reopened Ffox, switched on sync in add-on settings and it put all the TMP containers back in.
Oh and it's now synced a website back into a container I had removed it from on both machines.

Clicking "Remember this decision for this site" or manually changing the site list for a container are ignored or overwritten. It keeps asking though as-if there is any function in any of the controls.

WHYYYYY? What is the intended purpose of any of these functions if all it does is sync back over the top undoing everything I do to try to clean up the mess it keeps replicating?

A community of conscientious supporters' time and energy would be better spent on how it /should/ work, why it is important in theory, and improvements - instead of barely getting it to function as intended and repeatedly cleaning up the mess it spreads everywhere.

A mess admittedly created by Temporary Containers but I haven't had that installed for several years but still have several hundreds of TMP containers to delete. Again.

Good theory.
There is a way to remove the hundreds of synced TMP containers created by Temporary Containers extension, but sync just undoes everything you do, so good luck.
Also ! Watch-out! The page jumps around so if you are trying to use it for what it's for: bulk removal, it's easy to delete ones you wanted to keep.
about:preferences#containers

Toda vez que vou abrir um link, fica me perguntando em qual container eu quero abrir. isso é muito chato. Queria uma opção para evitar essa pergunta. antes estava maravilhoso, eu controlava rapidamente em qual container gostaria de abrir um link. Agora parece que sou idiota: "Você quer mesmo abrir esse link nesse container?".

Incessantly asks if you want links open in current container or not. What a stupid and illogical behavior to program into an extension. Smarten up.

I love this extension very much, but after updating, the "Open this site in your assigned container?" appears and I don't know how to disable it.

This page is so annoying and didn't help anything.

every time I open a new link? This is so annoying!
"Open this site in your assigned container?"

How do I remove "Open this site in your assigned container?" every time I open a new link? This is so annoying!

This add-on is not working as advertised. When closing multiple windows (or sometimes even just one) all the assigned containers are lost on restart. Also, closing and undoing the closing of some tabs causes the container to be lost as well.

Screw latest update, i use this extension for working, opening company website for different roles. Because of this update, i had to confirm when i open a site on another container. Sigh, you slow me down

Please optimize this extension for Firefox Android

This extension was great until the update that removed the option to do not force to open a site on some container, and normally run on default container again.

"Hide and Show" feature is advertised, and I selected and installed the Add-on exactly for this use case. Now I can't find the feature. Can you please point me to it ?
See 2 "discussion" on this page related to the feature. My Conclusion: Falls short of this advertised use-case. Rating down for the time being until the discussion brings a solution to the restrictions.

You can lose your data. Do not trast this add-on! Very raw product.

Good idea in principle, but will only work with my email account for a week or two, then instead of opening container it throws me back to the email log-in screen. If I disable or remove this add-on, all is well.

Does NOT work in private tabs!
I always use private tabs by default, once I installed the extension nothing happens.
I've checked the permissions and there's no way to allow it to work in private mode.

A real shame!

no longer auto opening tabs in the correct container that ive assigned them. not even facebook.

Le raccourci clavier Ctrl + . (point) n'ouvre pas le panneau contextuel.

It doesn't remember your login details and you need to log in every time

I breaks Distrokid's claim YTube artist page, and works weird with Google, it constantly ask if I want open something in other tab which is annoying.

As soon as the extension is deactivated, almost all data is erased! There is no way to recover anything and you cannot make a backup! This makes it INUSABLE. This is a very serious problem that has never been solved!!! Why don't you use Firefox Sync?