No...that's not (totally) correct. What @RiverSmallieGuy is referring to is this: If you mix up a set amount of epoxy...say in a small cup. The thick mas of epoxy will set off an exothermic reaction and set up really fast (as well as get hotter than hell). By spreading out the epoxy you are retarding that reaction ...thus extending the life of the pot.
There is no discernable difference (in cure time) in applying a thick of think coat of epoxy.