Aside from it just being a scientific research project, in practice even if they were produced in combination it's almost certain that they would be refined and purified for medicinal use.
But it would be much easier to not have to separate them and do one molecule per plant/field.
That aside your monoamine oxidase would prevent all but the psylocin from being orally active. Maaybe if the tobacco were very carefully dried and not fermented you could smoke it.
Now if they were to engineer in some harmaline/telepathine and put it into a tomato you could make some very special marinara sauce. The acids would act like a 'lemon-tec' and heating could perhaps be doing some decarboxalating. I have no idea if people experiment with mushrooms and ayahuasca simultaneously.
I can't wait for the Epstein Class to start raiding pasta shops to protect their black markets. :/