Editor V1.36n-B released. It's a very minor (but useful) update, it just adds a scrollbar to the menu for selecting terrain pieces / objects.
Do note that this scrollbar, even when scrolled all the way down, doesn't seem to quite go to the bottom of the available pieces. There isn't much I can do about this; as with many parts of the editor's source code, that menu does not play nicely with Delphi's IDE. Still, it's an improvement over not having one at all.