It's not made clear what exacly 'FLOW' is composed of.
Could it be a return of the George Mardquandt model where top-tier dealers i.e. people who deal in hundreds of kilograms of H were offered an active cut that would have the same duration of heroin but in essence meant they could double their profits instantly.
That only fell apart when some idiot attempted to just cut aMF into an excipient and attempt to sell that to make even more money (Grisham's law again) because it turned out that GM had been at it for three years.
I've never believed the self-publicity GM went for. When aMT (and 3MT) were both controlled, he could in theory have made a still legal analogue. What George doesn't want you to know is that the key precursor in the synhesis of aMT is BMK. Yes, the same BMK that's so frequently used to make methamphetamine. So my theory is that he had a connect for the BMK, mastered a single step and pushed it.
If science should teach us one thing, it's humility. The more you know, the more things you don't know (and repeat...) because science is a process and people who obsessively collect papers miss the point. Half of those papers are likely to have been superceded by new findings. They also appear to assume an in vitro model is a GOOD guide to in vivo experiment - mostly they aren't. Then the in vitro models almost always use a specific strain of white mouse and again, that's still not a good guide to how a compound will act on homo sapiens.
GM was a massive self publicist and I posit that no, he worked out how to make meth and how to perform a single step taken from a Janssen patent. I could do that - which is to say, anyone could.