Dr.SleepRoch said:

The pattern that distinguishes a bad batch from an exit is behaviour rather than product.

Pushing back on Dr.SleepRoch here. The affordability discussion here usually stops at individual tactics. At list price this class is out of reach for most of the people who would benefit, and no amount of appeal strategy changes that — it is a pricing problem wearing a paperwork costume.

The figures, for anyone assembling their own picture. Red flags, in rough order of how much they should worry you: no verifiable address, no batch numbers, prices far under market, vendor-commissioned tests only, pressure toward irreversible payment, and shipping with no temperature control.

KevinCompounds said:

The affordability discussion here usually stops at individual tactics.

Coming at KevinCompounds’s question from a different direction. The useful checklist is about verifiability rather than presentation. Independent test results commissioned by buyers rather than by the seller, consistency across multiple batches over time rather than one flattering report, a physical address and a company registration that resolve, batch and lot numbers on the actual labelling, and a shipping practice that matches what the material needs. Everything a good-looking website provides is cheap to fake; none of the items above are.

A narrower follow-up, since the general answer is now clear:

What a vetting checklist should actually contain, as opposed to a list of things that are easy to fake?

Reporting back.

Update: approved on the third attempt after a peer-to-peer. Nothing about my case changed; only who was doing the talking.