Unfortunately middle-clicking tabs at the upper edge (to close them) is still not working inside of tab islands. Also no mouse-over information is coming up at that spots.
So tabs in tab islands have different behaviour than tabs outside of them. Thats even more annoying than before. Also the Opera Button on top left and the + button to add new tabs are still not working when clicking on their top edges.
Thats really not good and consistant design. All tabs should behave the same and be clickable as a whole up to the top. Otherwise I find the bahviour just annoying and, for me, tab islands a born dead.