A Direct DME High Temperature PEM Fuel Cell

Direct methanol fuel cells are a quite well established technology today. The conversion efficiency is not as high as for hydrogen powered cells, but the energy density and ease of handling and storage of methanol offset this in several applications. DME is a comparable synthetic fuel [1] with a specific energy similar to ethanol, i.e. significantly higher than methanol. Why not convert DME directly in a PEM fuel cell like we do with methanol?