When you want to scroll through the custom tags in that panel, the scrolling goes very slowly.
In my opinion it would be better if it jumped at least a whole custom tag line per scroll-wheel click.
Using the scroll arrow buttons is even more slow and practically unusable.
Also when you scroll somewhere in the yellow area, instead of the panel scrolling, a drop down table opens immediately.
It would be nice if that would only happen after you had first selected a field there.
The same goes for the tag editor panel when docked at the bottom of the main panel.