KATE tab bar is no longer configurable like a KATE one was in KDE4.
Could you please be more specific which feature you are missing?
Everything that was in the other tab bar in KDE4. The current one was kept from KDE4 but is the one I didn't use. I can't get to KDE4 for a few days, but I'm sure someone here who programmed that, or used that, could list everything the other one did. Or, if you've all decided to discontinue that one, never mind. If not, I'll get back to this...
Are you talking about the multiline-tabbar, or the toolbar-like tabbar?
Multiline tab bar (since the other, plain tab bar seems the only option, not configurable, doesn't scroll.) Now that that's stated, I don't think I'm going to list features you already have in archived code. Now I'm using a tab bar that works better (in another program... because I also reported another tab bar inadequacy/bug; ) if KATE improves, I'll switch back.
*** This bug has been marked as a duplicate of bug 386758 ***