Steeping is something you do with tea... aging is the proper term, you age juice, wine, etc. and to be honest, "steeping" juice is a waste of time with non NET juices. Try it out when you get it, if you like it vape it. It may get better as it ages, it may get worse. As far as NET juices go, then yes, aging does improve flavor due to the complex chemistry of the juice. I have found that the flavor characteristics in NET's do improve over several weeks... but they never last long enuf to get past 5 or so weeks anyway...
Very interesting you comment on worse. I seem to take a very strong flavor (I LIKE!) and as it ages the flavor drops. This seems to be accompanied by a very dark color and increase in viscosity. It appears certain blends will hit the mark in a few days then on to the refrigerator.