Seeing as how a single Bag of Fertilizer yields 1x Acid, 4x Fertilizer when scrapped, I thought "brahmined" settlements ought to produce acid alongside fertilizer, no?
Because Reasons.
You will still have a 25% chance of producing nothing per settlement, but now you will have a 50% chance of producing either 2x Fertilizer or 1x Acid per settlement when you do. Hardly noticeable early game, mind you. And you WILL still need Brahmin in your settlements to get these benefits.
Also, as a bonus: A certain Ghoul in Goodneighbor will sell small shipments of Acid when properly assigned to a player-owned vendor...
Kindly report bugs, etc!
PS: If it seems the acid to fertilizer ratio doesn't make sense, let me know as well!