I've noticed for a while now that when looking for cubes to complete vote, there are a lot of tiny corner cubes that are almost impossible to see without getting up close to the branches. I believe I have a solution which might be relatively easy to implement.
While in scythe vision, or any of the other view modes, a legend appears with different coloured squares representing the state of each cube. If one were to take that already existing interface and make the squares clickable, they can be programmed to hide the relevant cube.
By doing this, you could for instance, hide all cubes that have the required votes, so that you see just the cubes that still require your attention.
An alternative to this, which might be even easier to implement, is to have an option to view the placeholder cubes that you see when you initially load a cell. Before the branches become visible on a cell, you see nothing but actual solid cubes representing each playable cube. If a button or hotkey could be implemented to switch to this view, finding the cubes you want to work on would be significantly faster and easier, especially in cells that are nearing completion. With this idea, the feature already exists. It just needs a way of being called up whenever the user want's it to.