An instrument simply aging, does not improve in tone. The instrument must be played, for the tone to improve. Luthiers and players describe it as the instrument opening up. Some have done experiments, exopsing the instruments to extreme vibrations. It was found, that the vibrations did improve the tone of the instruments. I have a feeling that, using a cue, improves the cue's hit over time. Of course, some think I am nuts for thinking such, so take it with a grain of salt.
Tracy