Pretty much as everyone else has mentioned. Waaay back when my imaginary evil twin sister was in the black market pretty much anything could be had and it wasn't a factor. In the very DL but highish consumption days strain tolerance was an issue. FF to consciously using medicinally and shopping on silk road and she simply kept a large variety on hand. FF further to getting a medical license, tapering down and cultivating a sensitivity; i.e., mini dosing? Switching up strains and vapes even a little bit and tolerance is never an issue. Vapcap is the only device in play now a days and something as simply as switching between heating methods works for alternating vapes.