While I'm not sure I truly understand the definition of steeping....I had an experience where I let some juices "age" for about a week. There was a menthol
juice that went from trash to treasure in 1 week.
http://www.e-cigarette-forum.com/forum/diy-e-liquid/152724-flavor-difference-pg-vs-vg.html
To summarize that thread: I ordered 5 bottles of
juice from 2 different companies. All 5 had a perfume-like quality to them. It was so bad, I couldn't use 4 of the bottles at all. They just gave me a head ache.
The one I could deal with was an RY4 mix. The next day, that RY4 was much, much better. The day after that, it was border line amazing. On the third day, it was just full of all sorts of awesome. The forth day it was gone

(well, I have a few ml left. I was
vaping it so much, I made myself sick. It's only 12mg nic!)
...during that time, I tried the menthol and it was my all day vape for a while. I keep the empty bottle on my desk now as we went through some ups and downs together

(actually - I keep the bottle so I know where to get it again when I do another order. It ended up being exactly what I want; a "curiously strong" menthol - nothing else. I'm going to see if I can order it by the liter instead of milliliter)
All 5 bottles lost that perfume...but that RY4 and the Menthol ...OMG that menthol.
sigh...I was trying not to place any orders this week...but now I'm going to have to.