Can I hide a tag class from my titles?

Yes, you can! Head to "Tag Management" on the left menu and click the eye icon next to the Tag class:

Now, the entire tag class is hidden. To make it visible again, simply click the eye icon. Now the whole tag class is not visible. You can change it back by enabling the eye icon again.

To hide the system tags ("Scopus #2"), you first need to enable the "Show system tags" slider:

Now scroll down where you can see the "Scopus #2 tags" and click on the eye icon:

The system tags are now invisible to you. You can make them visible again by clicking on the eye icon again.