I think you might be right on this. Whenever I get a bottle, I let it sit open (cap and tip off) in a dark spot overnight just to let it breathe a bit. That seems to make a good difference.
i've talked to a number of people via email and other ways who actually make the juices...people like Wlad at Ahlusion and Don over at BWB, and the one guy from Vermillion River about steeping
to most of them they agree it's way overblown, they do agree that a few days or so can give a tobacco flavor a bit of time to mellow
but all 3 of these have told me not to steep with the cap off
Wlad states emphatically that his aromatic tobaccos require no steeping at all, probably because the tobacco has been in whatever liquid he's using to extract it for a considerable amount of time
so anyhow, i think steeping is way overblown for 95% of juice out there
some people will come on here and show photos of how their juice darkened over time, they are right anything with nicotine in it is going to darken over time, this is the nature of nic, but it doesnt mean the flavors are becoming more melded together or anything