I hacked Cthulhu Dark a couple times (into a time travel game and a steampunk ghost hunting game, plus an occult western where it's hacked until the game is nearly unrecognizable). Adding more Insight-like numbers works great when you have different, bad endings for each die. So in the cowboy game, you have your "Way of the Gun" die. When it maxes out, you are gunned down like a dog. If you max out in "Way of the Drifter", you wander into the desert and are never seen again.
The cool thing about doing that is it forces the player to make some interesting choices other games don't. Most games encourage you to find ways to make your best skill applicable to all situations. But this does exactly the opposite: use one method to solve all problems and you're out of the game quickly. So every character wants to show different sides at different times.
I love hacking Cthulhu Dark. It's got a lot of potential t be applied to a lot of different stories in different ways.