In POLYAREA_BIGDANGER cost is 500 yards by yard.
If crossing the BigDanger zone has a lower total cost than going around it, the bot will cross the zone.
m_filter->setAreaCost((int)PolyArea::POLYAREA_GROUND, 10.0f);
m_filter->setAreaCost((int)PolyArea::POLYAREA_WATER, 120.0f);
m_filter->setAreaCost((int)PolyArea::POLYAREA_ROAD, 1.0f);
m_filter->setAreaCost((int)PolyArea::POLYAREA_DOOR, 1.0f);
m_filter->setAreaCost((int)PolyArea::POLYAREA_GRASS, 20.0f);
m_filter->setAreaCost((int)PolyArea::POLYAREA_JUMP, 15.0f);
m_filter->setAreaCost((int)PolyArea::POLYAREA_DANGER, 40.0f);
m_filter->setAreaCost((int)PolyArea::POLYAREA_BIGDANGER, 500.0f);
You can try to bypass the area (BigDanger area) with "ROAD" type.
By default, "Ground" type is used (with cost of 10)