You're welcome. And I believe your guess is right. I had that kind of issue with my old machine, years ago. I tried again and change the size of the brush similar to the head, and still perform well.
Also, I found a bug, not sure it is here where I should report it. On any conditions I can't make 3DCoat to calculate Curvature or Cavity data on Paint room. It close the program on each attempt. Using 4.9.69.
Calculate Cavity is needed to use smart material. Wonder if anyone else has the same issue, or it is just me. Thank you!