It is sometimes tricky to get an accurate edge while using voxel scrape tool. When the brush is over the edge, scrape "tries" to bevel it. And if not to touch edges or corners, some welts appear. Avoidance of this things can greatly improve hard surface modeling workflow.
I can now suggest only one way to solve the problem: add an aditional control for sampling area of scrape tool. If plane for making scrape is approximated from smaller area than scrape affects, user can "polish" edges safely.
По-русски. Скрейпом иногда довольно сложно нарулить аккуратное ребро - появляются скосы либо кромки. Предлагается добавить ползунок для регулирования размера области "отбора пробы" для усреднения срезающей плоскости.