There are artifacts to address this, think those are enough. Do we really need powers for this? Seems like it would be lesser value than SM or SAC, and it would just result in getting more of these type of powers and less of the others from wheel spins, etc.
There are artifacts for everything, but the one thing I find myself waiting for at the end of levels is for crafters/smelters to complete the techs, I got all the ores and armies I need, so SM or SA serve no purpose whatsoever at that point in time.
The only power that can really help out is a time warp, but that affects everything. Hence, the call for a power that makes a crafter or smelter works 20x speed for 5 or 10 minutes.