Well that's the coolest part about this, everything is based on the existing research.

The drugs they're making are the exact same chemical compounds formulated by the drug companies, and contrary to popular belief, the compounds can actually be relatively simple, it's the process of finding which compound that takes the most money from R&D.

So if you have 2-3 very standard chemicals, with well known reactions and outcomes, and you have the exact blueprint of what the final result should look like, and you can chemically test it afterward to see if it combined as expected, then anyone who has enough reason to use this instead of traditional means (i.e. being priced out of lifesaving medication completely) can be reasonably confident it will work.

Obviously the people who would benefit most from this technology would prefer a doctor and pharmacy to be involved as well. The point is that personal preference doesn't really mean much when the preferred option is inaccessible and the alternative is death or a dramatically reduced quality of life. You do the best with what you have.