On the one hand I really like the idea, on the other I think the return on investment and opportunity costs are too high.
A feature like this will take tremendous amounts of time to design, implement and balance. The trade-off is what else could be done with that time (power creeps ) and what that would gain.
I think while this is fun, the costs to design it are disproportionate to what it gives back the players.
Then again, it would really contribute to the "end game" - I can imagine a point where your code nears 'completion', and this would throw in a reason to stick around.
It's a trade off and I don't really know what my choice would be.