With the epoxy cured in the grip, I reinstalled them and tightened the set screws down. The grips are rock solid now and don’t move at all.
Next, I installed the screws that tie the fuselage center section to the lower wing skin. I had waited to do this until some shorter screws showed up. Van’s uses -8 screws all over the airplane when shorter screws are sufficiently long. I’ve tried to use shorter ones where I can to save weight.