I know it is not yet the time for spacial wishes, but since such a feature could help people to work more efficiency, if they write the way as I write, I am cheekily enough to post it as a matter to consider.
There are the keyword HUD, which is invaluable to take track of ideas and concepts - for which I employ it. Since I am writing theoretical scientific stuff, I use the keyword HUD to get hold of my special terms - which sometimes are very specific in meaning and usage.
What I miss now is my definition or use of the keywords ready to hand. A explanation or definition column right beside the keyword in the HUD as an option, just to add some line of description or info to the words. As a work around I maintain a list in a text file - but I am unsatisfied.
I even can imagine that fiction writer would find such an option useful as well, to have some descriptions of characters or places at hand.