Another thing that
Tree does properly, and which 004 would certainly need, is tabbed multiple hoisting.
In Tree (background of the image below) you can have several sub-trees simultaneously hoisted, each with their own tab, and this makes rather light and rapid work with larger trees.
In 003 (foreground of the same image) we have just a single window to work with, and quite a lot of heavy hoisting and unhoisting to do if we need to move around our sub-trees, or even just take a glance at the top of the tree.
Request for 004: tabbed multiple hoisting ...
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