Firefox Multi Account Containers vs User Profiles [3]

After a bit of playing with a few settings I am returning to my expectation of multiple FF profiles to handle container isolation-like capabilities. The problem with containers is when you do need tracking information to be exchanged between Facebook and another site. With my WordPress blogs they are set to auto publish to a Facebook page and without being able to selectively disable the containers they will not be able to authenticate with Facebook. I have found that the settings keep getting lost or turned off probably because the Facebook cookies are getting deleted or being isolated in the Facebook container which the WordPress tab can’t get access to.
Firefox has always supported multiple user profiles. There is a built in user profile manager which you can bring up by starting Firefox with the switch -P. This then gives you a list of current profiles and the ability to create delete or rename profiles, and to select a default. In this case since I have both standard Firefox and Quantum, there are profiles for both editions (Quantum’s profile is called dev-edition-default). 
After completing the process of creating profiles via this screen, you’ll want to make sure you have the default one selected as the one that FF will start up when it opens, because you want to start a specific profile with a custom shortcut (and you’ll probably want to have custom themes, home tabs and bookmarks in it so you can tell it apart from the others, too).
To start a browser with a specific profile, you need to ensure you have the correct profile name to pass into the shortcut. You can type in “about:profiles” in the address bar of the browser to get a list of the profiles the browser knows about. However, the list is only updated each time you open the browser and that means if necessary you have to close all windows of that browser to get it to reload. In this case I had created my profile list with regular Firefox and because Quantum windows were still open I had to close them all to get Quantum to show me the profile list.
The command to start Firefox with a specific profile is firefox -P “ProfileName” and it opens that specific profile. Plain old FF with no parameters keeps on using the default. Quantum has some way of seeing there is a dev-edition-default profile and using that instead of the one regular FF is using, which I think is the result of a setting in Quantum’s preferences, that tells it to start up with that specific path. If you are using Quantum alongside Firefox the command to start Quantum will be different. I have installed Quantum on some of my computers inside my home directory, instead of a system path, so that I don’t have to reinstall it each time I reinstall the system. This is also impacted by the fact we install Quantum from a TGZ file we download, rather than from our distro’s repositories as a DEB package. It also ensures that Quantum is able to update itself in our user account’s name (i.e with the right permissions) when Mozilla tells the browser to update, as if it was installed in the system path e.g. /usr, only root would have rights to that path.

So in this case to ensure I am starting Quantum I need pass the whole path in the shortcut. With the command line as above it indeed starts up Quantum with a completely different window that has nothing: no shortcuts, theme or extensions. I can now completely customise that profile independently of any other. What I really do need is a custom colour, or maybe changing the string in the title bar. And that I will look at next time. But for now I don’t need the multi containers because that window is only being used very specifically for that blog’s WordPress account. So that is how it will happen from here. The next thing is to add a custom shortcut in KDE Menu Editor and I will create a new submenu for browser profiles as well. Well I have been setting these profiles and shortcuts up and creating icons for them out of the profile pictures I use in FB so it is going pretty well and I need to install the Tab Session Manager extension into each profile to save the tabs and the NZ Rail Maps one will need the uget extension as well to handle the downloads. And so it goes.