My guess, which is simply that at this point, is that a formula may indeed be possible, but it would not be a simple formula. It would involve numerous variables, some of which are very difficult to assign values to. For example, the volume of air being moved past the coil per second would play a role, the volume of vapor produced per second as well. Then you have variables related to the heat flux of the coil, and possibly even coil efficiency coming into play. I'm not sure I could even begin to put together a proper list of all the variables that would need to be part of said formula.
So while I technically disagree with Boden, because I think a formula could be arrived at, I don't completely disagree with him because I don't think it would be practical to define it, or once defined to measure some of the things that need measured. You can't leave all those variables undefined after all.
If you really really want to work it out, get a bunch of volunteers. Break them into subgroups. Each subgroup gets a standard nic solution at several data points, maybe 3, 12, and 24 mg for simplicity. Stick flow meters on the drip tips. Measure volume of each inhale, which will give you known nic intake. Draw bloods at time early time points from the inhale and quantitatively measure nic concentration. Compare total inhaled to serum concentration achieved. If the serum levels rise in a linear manner, you can now extrapolate nic concentrations based on the test liquid chosen. If it is nonlinear and plateaus, that is, at a certain point you just can't absorb anymore, you'll have to choose concentrations that allow for variance dependent on dose administration.
With that knowledge, you can now go to town with different coils, liquids, and wattage and follow concentrations to see what variables produce what effect, possible allowing you to then create a formula. And if in fact it yields a consistent result which can be duplicated by others, I vote for naming it Boden's law, for the person who led the way to the scientific understanding of vaping.
Hell, even the FDA might like it. They love convoluted stuff like this in applications. Doesn't matter if they understand it, but it makes them feel like they're as smart as you are.
The above is a broad outline subject to revision, does not represent a formal proposal, has not been approved by an institution review board. No animals were injured in preparing this back of the napkin thought experiment.