Man, my buddy ran a little bakery out in Greensboro and had the exact same fight with himself. He scooped for years and his loaves were all over the place, some tight and some flat, and customers kept asking why Tuesday's bread was different from Friday's. He finally grabbed a cheap scale off Amazon and weighed his flour just once to see, and the same "cup" he'd been using came out to 5.2 ounces while the recipe assumed 4.5. Once he fixed that his bread got way more steady, like same loaf every single day, and he said he stopped guessing.

Learned that lesson the hard way on a customer's Roubaix last summer. Did almost the same thing you did, chased the cable and the limits for way too long before I finally stuck the hanger gauge on it and found it was bent. Now my order is dead simple and I don't skip steps: check the hanger with the tool first, then check cable tension, then limits, then b-tension. Takes two minutes to rule out the hanger and it saves me from looking like an idiot for three hours. People forget that hanger gets bent from the smallest tip over or even a bad shift under power, and a few mm is all it takes to throw everything off. I stopped trusting my eyes on hangers years ago because they lie to you. Buy the gauge, use it first, thank yourself later.