I love the nested hierachies of lists. However, when there is only 1-2 items under a parent, it is takes up a lot of vertical space to leave it expanded.
I often find myself adding a colon character to the parent item, and write the first things there before creating a hierachy, but when editing the node, and adding more children to the list, i then have to manually copy it to separate items.
Consider showing the first item next to the parent text, when you collapse a node - or showing the first 50 characters of the sub-level items in a light gray text.