Any chance you have a picture of what you're describing with the skewer? Not quite following, but I just finished an Eggscaliber and haven't launched it yet. Would love to ward off any issues ahead of time. Thanks!Now for rockets like the PNC-56 Egg Capsule nosecone (Found in the Estes Scrambler, Eggscaliber, TARC assortments, and the old Enerjet 1340/20 kit), with the tiny ring like the PNC-55AC, I cut away the ring, and using a metal BBQ skewer, make a memorial ribbon shape with a length of that. then drop it in from the top and epoxy it in place (closing the hole). I've had ejection performance tests (blowing from the bottom of the rocket to pop the nosecone off), where the top of the payload section or the nosecone of it come away instead of at the transition/booster joint. Of course taping the nosecone on, and gluing the payload section's cardboard to the transition will reduce the likelihood of this happening, the sealed hole further reduces the chances of this occurring in flight.
This problem of popping the payload section off also occurred with a balsa bulkhead, so I advocate for sealing that off with a piece of paper glued in place (name and email address written on it first) to form the "plug".