It has been suggested that scepter of time should maybe scale with the level of the tower that it is on, the only downside to increasing the time is that it would make enemy calculations a bit more intensive. 40x may not be feasible, but maybe like a 5x could be. It would be nice to hear from Andy on this one.
I found a duplication bug last patch. 2 scepters is playable. 3 was almost too fast, and I lost in a blink of the eye once. that being said I didn't abuse it for anything else and it was removed in 1.2 bc I reported it. I definitely did abuse using two scepters tho. no guilt there.