To navigate to a Directory listed in the Treespec History -- (if that directory currently DOES exist) -- the user selects the listed directory in the History list, and presses the Enter key.. This moves the cursor to that directory, in the Directory view, and it also "moves" that directory-entry to the bottom-line in the Treespec History list (if it's not already in that position).
However, when the listed directory in the Treespec History list is "obsolete" -- that is, when that directory does NOT currently exist -- then nothing happens when its History-line is selected, and the Enter key is pressed.
Unfortunately, this "nothing happens" includes the fact that the "listed" (but obsolete) History-line is NOT then moved down, to the bottom-line in the Treespec History list -- (similar to the behavior in most other ZTW History lists). Here, adding this "missing behavior" would be a useful improvement, because it would enable either an immediate "edit", or a speedy deletion, -- rather than leaving the obsolete, "dead entry", unseen, and cluttering the history list.
Also, when "nothing happens", (because that directory does not exist), the outcome could be improved, by using it to trigger the display of a temporary message: ... "Directory Does Not Exist" ... located in the Treespec input line -- that now appears (at this point), only as an empty, blank input field.
Bill