Uncertainty about added repos

[Forpli]

I'd like to ask a question about added foreign sources.
I read that e.g. the added (via terminal) Mozilla repo isn't shown at Software&Updates >Other Software
So is the GUI not for both -
/etc/apt/sources.list
and
/etc/apt/sources.list.d/?
Or are not all foreign sources shown there?
Does this mean it is sometimes necessary to search for the repo files in this file/folder because they can't be found with the GUI?
And does this mean: When they aren't shown in the GUI they can't be disabled only removed (e.g. before an upgrade)?

New Mozilla own Repository

Hello Ladies and Gentlemen! I want to change my Experience with the new Mozilla Repo and the Installation of Firefox. I used the Mozilla Guide to add it and it works good for me. I had no Problems and Errors. The Preparation to have wget and create the Path /etc/apt/keyrings I didn't have to made because it was already in Zorin 17. So, I used the Commands and controled the Fingerprint and that's it. At the End I used the Command to change the Priority and that works good, too. And now I have …

Until now, I always assumed that all added ppas and repos were displayed under Software&Updates>Other Software.

[Aravisian]

@Forpli

Or are not all foreign sources shown there?
Does this mean it is sometimes necessary to search for the repo files in this file/folder because they can't be found with the GUI?

Yes.
Mozilla chooses to use an Install Script with .list, rather than a readable source that the Software & Updates GUI app looks for.
Maintainers may not include the necessary metadata for the GUI to display.

[Forpli]

Can they also be disabled? Or should they be moved manually to another place where they aren't found when upgrading.

[Aravisian]

@Forpli

Can they also be disabled? Or should they be moved manually to another place where they aren't found when upgrading.

Yes, just like using ~/.config-bak, you can create a backup folder and place repository sources there to "hide" them during upgrading.

[Forpli]

Would it also be enough to add .bak behind .list and leave them in place?

[Ponce-De-Leon]

As an alternate to @Aravisian's Idea: You can go in the Repo File and set a # to comment it out. Then make a sudo apt update to refresh the Sources.

@Forpli

Would it also be enough to add .bak behind .list and leave them in place?

Would be an Option, too. But a sudo apt update would still be neccessary. You could test it and simply do it - for Example with the Brave Repo. Change it, see if it works and then change it back.

[Forpli]

Thank you very much for the tips. I tried it with brave repo with both options.
Adding a # disabled it (but was still shown in GUI), adding .bak removed it from GUI.

[Aravisian]

There are two standards on sources.

It is listed in the sources.list File. and these can be "commented out" with the hashtag.

And there are source files in sources.list.d, where .d is Directory and these cannot be commented out, as they are not a listed line inside a File, they are a file list of their own, inside of a folder.
Those must be moved to a different folder in order to be "out of the visible path" the GUI is looking for.