Yep - SOLVED - it was indeed the Ambient Occlusion (SAO). When disabled the dots disappeared, and remained gone regardless of nVidia driver or ENB settings. Only I though this is odd, because I had been using it before. I did find that, after some further research & testing, I can use it but only if I also use NVHBAO - that seems to help smooth the rendering significantly.
Used FO4 Configuration tool by Bilago
parameter search terms SAO & NVHBAO
Big thank you for the help!!