Well, I think 4mmc is now a controlled drug in nearly every nation on earth. It isn't explicitly listed in the UNODC list of controlled drugs but within the UK, EU, China, Russia, Australia, Japan, Mexico and Switzerland, it is illegal.
That means that it's reasonable to conclude that it is being produced in improvised clandestine labs. It does benefit from the fact that all of the precursors are cheap and widely available and the synthesis none to complex BUT a quick image search using Google shows the circumstances under which it was produced back when it was legal. Now I would expect labs to resemble the ramshackle meth labs so commonly found in places like the USA.
You certainly will not be provided with GC-MS/NMR data and since the world of illicit drugs strictly follows Gresham's Law, these people will push for the very cheapest synthesis possible. I know the price 'soared' to £3000/Kg when it was controlled in China.
So the usual risks of not knowing what is really in their, how much active is their and what adulterants are present all apply. If RC vendors still supply ephedrone, that might be safer.
But as with all these things, sooner or later RC makers are certain to stumble upon something that produces chronic toxicity. Aminorex & 4MAR both caused a great deal of fallout (the former having been widely used medically in Germany).
BTW also, their are some VERY similar compounds that remain legal (as fat as I know). I was given a sample of the stuff in the image below back in 2012. It was nasty to snort as it wasn't soluble enough but making the sulfate or phosphate would have solved that issue.
Image 1-png hosted in ImgBB
ibb.co
If anyone knows different about the legal position of the above, please correct me. At the time I lacked the knowledge in formulation to realise the problem but a year later we DID swap addition salts for a couple of products and it worked. It also kind of left the Chinese a bit lost. I don't think it's THAT complex which is a bit worrying CC the producers skill-set.
