I am the OP and I have mostly switched to Projected Meshes. I can work in blender for hours without having to worry about the buggy SDK interface. Some things I still add via SDK, mostly aprons.
I just wish the parameters of the material will work on PMs. If I change the albedo color, opacity, etc on blender, it does not affect the Mesh. I would have to change that in the png directly and that is when creating aprons is a little easier.
The best quality for the materials is seen by setting terrain LOD to 400. That is how I capture the screenshots for my products, but it compromises performance. I don't think to date, there is a PC powerful enough to run Terrain LOD at 400.