Right now, if you open a background tab and the hit Ctrl+Tab, instead of proceeding to the next tab (to the right without Tab Centre) as you’d expect, you proceed to the previous (to the left without Tab Centre). I think that either new tabs should be placed at the bottom or the behaviour of Ctrl+Tab should be reversed.
Either Ctrl+Tab should take you ‘up’, or the tabs should be ordered in the reverse direction. We read from top to bottom with is analagous to the right-to-left orientation of browser tabs without Tab Centre.
The next version (which I might have pushed a couple of days ago) switches the default back to opening new tabs on the bottom.