I can agree with the OP and I've been building coils for 6+ years now.
Something that I found that works, maybe it will help you out.
Ensure that you don't have any loose leads and that all the coils are compressed properly, the high end box mods tend to read ohm's at a rather high interval and will adjust without warning accordingly. I found that out myself and led to hot spots on the coils as a couple had fused together. Pulse heating is your friend at first, tap and go method that I often used on a fully charged battery with mechanical mods works wonders (or can start out a a really low wattage of 10 seems to help).
Keep your wicks wet at all times, although not confirmed yet by me but a friend who has the SMY says the ohms change when the wick is dry (which would increase your voltage at random). I've not seen this flux yet but I'd suspect that its there (and the volt meter gets use again).
Beyond that just fiddling with it until its right on spot really, I apologize that I don't have anything more to offer advice wise as I'm still learning the in's and out's of mine. I got it as a Christmas present so kind of newbie to this mod myself.