I blame sleep deprivation and post-fifth-revision-of-stupid-paper irritation. Take it with a
grain gallon of salt. And some emoticons
wait, not those emoticons!
But, yeah. The one thing the kobolds didn't realize was that dragons are nigh-immortal, and would keep growing... and growing... and before they knew it, the dragons were pretty much running the place. And it turns out that dragons draw their energy from the kobold race as a whole (due to their artificial creation), so as dragons became ascendant the kobolds, both individually and as a group, have weakened greatly.
Anyway, further back on topic, I suppose I'd let it work for the spontaneous subset of the spell list (for example, a cleric could sacrifice two orisons for a CLW), but nothing beyond that. Not that any of my players have actually asked.