The way a tab bar behaves, changing the currently focused tab when scrolling, (at least in KDE Kate) is inconvenient. I think scrolling on the tab bar should be like in Firefox e.g. it changes the tabs currently displayed in the tab bar instead of changing the currently focused tab. This change allows to move easily when there is a lot of tabs. If you ever implement this, know that one scroll should scroll about 6 tabs like on Firefox Ubuntu snap on X11 on Linux.