Generate Texture while KEEPING UV's from Retopologized Mesh?

I made a round trip from RC to Z-Brush and back as shown below, via these steps:

  • Reconstruct model in RC, export as .obj
  • Import in Z-Brush then decimate, retopologize as quads, lay out a symmetric uv atlas, then export as .obj
  • Import mesh in RC, texture and export as .obj

My question: RC has no trouble importing the quad geometry from Z-Brush (below, left), but after texturing RC’s export is as triangles (below, right).  I edited the .mtl sidecar for the .obj mesh to point to the texture RC exports, which is simple enough.  But I wanted to see if you’re handling the texture assignment in a different way.

Or are able to get RC to export quads directly?