a standing seam roof with seams that are 2" tall is acceptable down to 1/4 in 12 roof slope on panels less than 15 ft long in most materials. The problem is the perimeter capillary action. There are ways to stop this capillary action. Standing seam rake/gable, non-penetrated drip edge, and swabian eave detail.
The standing seam rake stops water from rolling around the side and sucking under the panel.
the non-penetrated drip edge allows a continuous cleat point necessary for wind protection at low slopes and acts as a capillary shield with a water stop at the back. the backside water check also allows cleats to be placed to allow thermal motion of drip edge. When using this type of drip edge to stop capillary action it must be set in a lower plane than the rest of the roof deck.
the main benefit of the swabian eave is that it sheds more water off the roof than other seam end details. most of the water on a standing seam roof runs along side the seams. the swabian eave detail dumps the water off the panel beyond the drip edge.