I've been tracking six vendors for 11 weeks, mostly to learn how to read COAs. One has a March Jano report for batch B2311, 99.1% purity, but the vial label in their current photo says B2405. Their site says same formula, new batch. I'm not asking who to use.
I'm asking how much weight you give batch-specific testing vs. old reports. Is a missing current COA an automatic skip, or just a yellow flag? What else do you check first?