Poser only supports one weightmap per joint, so it is incompatible with Daz "tri-axial" weightmapped figures, but DS supports both traditional and their tri-axial weight maps, so I believe that it is only the tri-axial weighting that is incompatible between the two.

Certainly, V4-WM poses in DS and when exported via Collada has all of her weight maps, so DS is keeping the "poser" weight maps.