Do you want the ones with feed analysis?
These are the ones I know of so far:
First & third posts in this thread:
https://www.backyardchickens.com/threads/feed-tests-more-results.1565804/
This thread, posts 6, 10, 12, 14, 18, 22
https://www.backyardchickens.com/th...en-feed-craze-posted-testing-results.1564737/
Post 581 of this thread (I think this link will go straight to it; same feed as the one just above)
https://www.backyardchickens.com/th...-to-be-analyzed.1561749/page-59#post-26554912
This is the thread comparing feed labels (spoiler: not much changed.) The labels are sprinkled throughout many pages, so this one isn't a quick read. I doubt your client will care about this one, as she probably assumes they changed the feed but not the label.
https://www.backyardchickens.com/threads/current-internet-theory.1561604/
As regards your client wanting something "better" for her chickens, maybe suggest that she try a particular kind of other feed. For example, "maybe you should give your hens chick starter instead, with a separate dish of oyster shell. They wouldn't bother to add an anti-laying ingredient to chick starter!" Or whatever else you think would work for her preferences (specific brand, different store, organic, soy-free, flock raiser + oyster shell, serve it as a wet mash instead of dry, try fermenting it-- the safe options are almost endless.) Some people respond better if you give one single suggestion, as if it were THE fix, rather than a list of options