If Cheat Sheeter is still being worked on I have a couple ideas if you have not considered them:
1. I use some pretty keyboard shortcut heavy apps (i.e. Blender), So having a tabbed interface for categories is almost necessary in those cases to quickly locate what is needed.
2. Would be good to have an auto hiding slide out drawer to switch tabs/categories.
3. Stepping out on a limb here, adding the ability to easily hook these stored commands to a custom radial menu or added into the context menu would add another level of use to it especially since it changes with the program... would allow for a lot of custom menus in different programs with a right or middle click... or again maybe a second hotkey... one for the reference sheets and one for the clickable menus. Slightly outside the stated use of the program, but closely related so I thought I might as well throw it out there. Anything to make getting things done on the computer easier.
In any case it's going to be useful either way, and I can see a lot of uses for the reference sheets alone.