  Using current technology, gravitational microlensing is the only method that
can measure planet masses over the full parameter space of planet and
stellar-host masses and at a broad range of planet-host separations. I present
a comprehensive program to transform the $\sim 150$ planet/host mass ratio
measurements from the first 6 full seasons of the KMTNet survey into planet
mass measurements via late-time adaptive optics (AO) imaging on 30m-class
telescopes. This program will enable measurements of the overall planet mass
function, the planet frequency as a function of Galactic environment and the
planet mass functions within different environments. I analyze a broad range of
discrete and continuous degeneracies as well as various false positives and
false negatives, and I present a variety of methods to resolve these. I analyze
the propagation from measurement uncertainties to mass and distance errors and
show that these present the greatest difficulties for host masses
$0.13\lesssim(M/M_\odot)\lesssim 0.4$, i.e., fully convective stars supported
by the ideal gas law, and for very nearby hosts. While work can begin later
this decade using AO on current telescopes, of order 90% of the target sample
must await 30m-class AO. I present extensive tables with information that is
useful to plan observations of more than 100 of these planets and provide
additional notes for a majority of these. Applying the same approach to two
earlier surveys with 6 and 8 planets, respectively, I find that 11 of these 14
planets already have mass measurements by a variety of techniques. These
provide suggestive evidence that planet frequency may be higher for nearby
stars, $D_L\lesssim 4$ kpc compared to those in or near the Galactic bulge.
Finally, I analyze the prospects for making the planet mass-function
measurement for the case that current astronomical capabilities are seriously
degraded.
