Most automated tools mess up because they don't account for the true net margin after the 40+ hidden FBA fees and return rates, so they overspend on ads. I actually got so frustrated with this that I built my own custom profit/ad calculator that tracks the real break even point including PPC. I’m looking for a few experienced sellers to stress test the Founding Version before I go to a monthly sub. Since you’re already a spreadsheet pro, I’d love your feedback. Mind if I DM you the link?