Actually, I'm sure no reputable vendor would KNOWINGLY sell unsafe tires.
The real question is whether the vendor knows, or can know, if a tire it is selling is safe or not. And the only way to really know this is to dissect samples for analysis, and then track the adjustment rate -- after it's in the field (and on your car). The vendor counts on the manufacturers to do that for them, with rigorous QA systems throughout production.
History shows that even the first-tier makers sometimes mess up. Michelin recalled a small batch of their excellent LTX M/S2s last year, and they're the best in the business. But at least they've implemented meaningful QA, as their hard-earned brand reputations are at stake. Michelin fixed things, and quickly.
In the first Chinese tire recall debacle, someone at a no-name Chinese factory decided to omit the gum strips to save a few pennies, and told no one. It's impossible for a retail vendor, whether a 4th generation Mom & Pop, or a national name-brand chain, to catch that. A national chain vendor doesn't immunize a bad tire. And then it's on your car, with your family in it.
Unless it's a Chinese company serious about building real market presence and brand reputation (e.g. Haier), and following rigid QC just like the global majors do, I still have reservations about re-branded or off-branded Chinese tires, regardless of who's selling them. The sweat shops making some of them (and some of their mystery materials suppliers) have no real brand value to lose, just the latest production contract.
For those thinking that generic Chinese production has evolved past that, witness Petco's debacle this week.
Whether Primewell is more like the global majors, with dedicated facilities it tightly controls and first-world QA, or is just a branded clearing house for tires made all over China, I simply do not know. Even if I were really strapped for cash, I would want to know that before I put my family on a set just to save a few dollars.
Meanwhile, a nice set of Generals or Kumhos is only a few dollars more.
There's a reason that cheap and value are different words.