Model a standard polygon model in Maya and maintain quads. If there is a hole in the model. Go to Tool -> Geometry -> Crease
Subdivide once if geometry has triangles to turn model into a 100% quad model. Use this subdivided version as level 1 now if this has been done.
Tool -> UV Map -> Delete UV
Tool -> UV Map -> AUVTiles
Do you painting and export the lowest level mesh as .obj
Now go to your lowest level of the model and to create the displacement map
Tool -> Displacement Map (use adaptive and smooth UV options on)
Now in photoshop
Edit -> Color Settings -> Gray -> Gray Gamma 2.2 (If done right. The gray value in the background areas of that texture will be kept at 129.)
Image -> Image Rotation -> Flip Canvas Vertical
Now Save the file with options "As a Copy" & check the "ICC Profile: Gray Gamma 2.2"
Links below included a reply from Cgbeige -> this allows you to scale the model and have the displacement maps hold up.