For me this isn't about "just a few tabs open." I use a big monitor (30" 2560x1600) and around 100 entries can fit on my screen at the same time in the Tabs Outliner window, which defaults to the full height of the screen. I'd love a "don't scroll if all the entries are visible" option. What ends up happening for me a lot of the time is something like this -- note the position and size of the scrollbar.