Not much play up and down, (maybe 1/8") but since there is no preload the top of the spring is free to move side to side. I simulated some weight by putting the jack underneath that wheel and it tightened up. Maybe it will be ok with the car on the ground but I am just worried like your saying that the rebound may cause noise.
With all that said, I don't see how it can tighten down more on the spring because the nut is fully seated on the strut.