"ah.. but in this case, it's a carbon steer, so that's why i'm pondering how to get the fork nice and snug with any play of going up or down (when the frame is lifted up)"

Unless I missunderstand your question-- there are inside the end of the carbon steerer devices (not start nuts) (plugs?) that both reinforce the steerer from compression as well as have a top cap bolt hole. (Compression plugs?) Some are internall expanding some are epoxied in place. Andy.