Aizatulin

UV-Transform looks like creep (only for polygons). This can be done (with VEX for example) if your geometry has uniqie uv-coordinates (1:1 mapping between uv and points). You can convert the uv geometry to normal geometry (P <- uv ~ uv-space) and capture the object you want to deform by the uv-geometry using xyzdist(), which gives you all you need to transform the back back onto the original uv-geometry (primuv()).
Here is an example (if you want to try)

I've watched a modo video about smoothing groups and it looks like, that they are seperating the borders between the groups. In fact, if an edge is between two different groups (only two groups at once), it should be a hard edge. There are many ways to define/modify groups in houdini (procedurally/manually) but I've no idea if there is an inbuild function already to extract the borders between the groups (similar to modo).
Fortunately you can create workarounds (using VEX) almost always, if there is not the right feature available.
If interested I've created a (more experimental)file, where you can extract the borders (edges) from all existing groups, if the edge has exactly two different groups as border primitives and nothing else.

Here is one way which should work:
for each edge (point pair) -> get both half edges -> get both prims (for each half edge) -> get all vertices for each edge point -> find for each prim the corresponding vertex for each vertexlist -> now you have two vertex pairs for each point containing the vertices of both prims -> now you can compare the vertex normals and if the angles of both pairs are greater than a threshold value put the edge into the group.