I'm not sure what question the OP actually wants an answer for.
One aspect of not lung inhaling is many people new to vaping have an "insult to injury" problem when they first start. They are already in such a state that they are having multiple smoking induced coughing fits per day. Then they suck down a completely foreign substance - containing PG which a lot of people do find irritating - and the experience sends them into even worse coughing fits than they had from smoking. So at least to begin, lung inhaling is generally not recommended - otherwise some wouldn't even continue with vaping due to coughing fits.
As to nicotine absorption, in case you didn't notice vaping is not smoking. You should have noticed that you do not get bowled over by a few drags off an e-cig and get an instant buzz like you do from a cigarette. Smoking = smoke. Vaping = liquid vapor. You are inhaling two very different substances and even by scientific inference some conclusions about the difference in absorption can be drawn. In any event, the majority of the scientific testing done so far has focused on what is produced in vapor, not how the user absorbs it. Here's a place to look at what we know so far:
Lab Reports: ecigarettes
Lung inhale, "cigar style" - do what works for you. But I don't think you are getting tons more nicotine from lung inhaling. One report even showed that harder draws off an e-cig don't produce more nicotine in the process. (But with a cigarette it does.)