My wish: I'd like a new GUI root (maybe in the bottom left) designed for short-life GUI elements (for extended info about hovered entities, for example). It should be
- rendered above the other GUIs,
- transparent to the cursor, i.e. doesn't affect player.selected and isn't clickable (both to prevent flickering issues when you hover over something, and to discourage other mods from using that root for more permanent GUI elements),
- without element packing (i.e. render each of its toplevel children in the bottom left corner, all on top of each other).