When expanding tags past the view height of the tag browser, the scroll bar appears. However, when you deselect all options (value, data type) in the column chooser, the scroll bar disappears even if the tag list is longer than the height of the panel.
Not sure if this is intended functionality, but it is a small annoyance. Sometimes there are instances where deselecting the columns to just get a decluttered tag list is helpful. Am I missing something?