Like many here, I find the Jagged Knife mega event to be a boon at best, annoying at worst. Most of the time, it allows one to take worlds from factions you don't want to war with. Even if most of the worlds taken are yours, you can usually retake them back in short order. Even in the worst case scenario where the Jagged Knife become a threat, they can usually be beaten back given enough time. Worse, the AI factions don't react to losing their planets to what amounts to insurgency in a realistic way. They treat them like a whole new faction that colonized a new planet. To sum it up, the Jagged Knife are essentially a minor race with a lot more planets.
What I propose is that the Jagged Knife event be converted into something a little more interesting. Instead of an insurgency, how about a coalition? Have all the minor races in a game team up to form a new Major race (Independent League maybe?) and give them all the best tech lines of the major factions. This would give them a pretty powerful setup and would be a true mega event. The fact that minor races tend to cluster together would also work for them. It would also allow the IL to use spies, be spied on, and vote in the UN, which could be a problem if that has to be recoded.
Too bad that it's probably too late in the beta for this idea to be seriously contemplated. :/