I installed an adapter not realizing the plug was missing, let alone that there's a thin plug. It turned out fine. I have been using the 5 min set and 30 min cure time epoxy and I use a wooden kabob skewer to apply on the inner walls of the adapter and on the walls of the tip to minimize the amount of epoxy that goes up into the shaft. The plug is about the size of the hole in a shaft tip, and there's a ledge in the adapter that about the diameter of the shaft walls, which is why I didn't notice the issue on the first shaft I installed.