There is a free Plugin for CINEMA 4D which is called UVtoObject. This Plugin converts the UV-map of the selected object to a flat polygonal Object. Now you can use any Polygon-Tool to edit this Mesh. All changes update the UV map of the original Object.
This works also with HB_ModellingBundle Sctipts like HB_SmoothEdge or HB_EvenDistribution.
Get UVto Object here: http://www.welter-4d.de/fplugs/freeplugins_en.html