Unless you’re getting your medication from a reliable dispensary, then you likely will never be able to track the genetics of the cannabis.
I don’t want to speak on oil as there is way too much variation in how accurate the reported results are. One study in 2016 found a 31% error in what was reported with respect to oils. I don’t know if adding a oil (CBD) lowers herbal THC level or not. I don’t see a point in that. Upper end portable vaporizer allow you to set the vaporization chamber temperature. THC vaporizes at 157c. (about 314 f) CBD at 160c plus. CBN, CBC, THCv all vaporize above 180. Good vaporizers allow you to set the temperature by degree. So you, in theory, can target what you’re after.