There IS a top and bottom on the chimney, and unfortunately I forgot how to tell them apart... I will see if I can find something about it.
I saw a post about this recently. I checked my authentic KFL+ and my R91s but both sides of the chimney are identical (no tapering on one side like I saw in a photo). Perhaps this is specific to a brand of clone?
As for over-saturating a wick, I don't know how that's possible. If you get too much liquid into the chamber it will gurgle and likely leak out the air hole. You may have reduced vapor production while you vaporize the excess liquid, but if you later get dry hits it points to an underlying wicking problem and I can't envision it being the result of over-saturation.