T1 | In the fictional B prototype check, two of three keyboard-only participants could not reach Save. This tiny case does not estimate population prevalence. B cannot ship with the blocker.
T2 | Repair M adds engineering 2, design 1 and QA 1 person-day to B's original estimate. Skipping repair or QA is prohibited.
T3 | C's prototype check found Next was mistaken for a payment action. A narrower wording-and-sequence revision C2 requires engineering 4, design 2 and QA 1, replacing F-C.
T4 | Mandatory A, capacity, budget and target date remain unchanged. No extra QA capacity is approved.