I'm thinking that it's easier to prevent getting too high, by changing what you use. The weed industry has their own "nuclear proliferation" scheme in which they are chasing higher and higher THC level (even 30%). I've concluded it's easier to avoid the problem, by using strains which include CBD, and relatively low levels of THC. E.g. Cannatonic. THC ~= 5.5% gets you high slowly, and the next breath is unlikely to put you over the top.