I've been waiting for years for this mod! Thanks a lot, keep up the great work!
P.S. Here's my attempt at making an Impact!-aimed vessel. A lander, 6 impactors and an orbiter, all in one package. Curiously, the separation didn't go quite as planned. I was planning to activate decouplers by hand, to carefully liberate the impactors one by one, after the lander is gone. But when I started to remove the upper-left tri-coupler by activating one of the three decouplers (thinking that tri-coupler will stay in its place for a while, being held by two other decouplers), then, for some reason, two whole columns of impactors have detached from the base (lower-right tri-coupler) on their own. Since I was building the vessel from top to bottom, I assume that the column I separated was the one actually holding the vessel tree together, while the other two columns were glued to the base by ReCoupler algorithm, which seemed to decide it's about time to cut the connection. Or something like that. I hope that was helpful.