The overlaps that I was getting last week were pretty egregious but I can’t deny that using the same version of Unity this week, the overlaps are much better. Last week I did try setting the “packing Iterations” to the maximum value and there was no observable improvement. I don’t remember if I tried to increase the “Lightmap Padding” from 4 to 8 but just now when I tried that, the mesh separation was improved and the light bake solution was much cleaner.
Thanks for taking a look at this and sorry if I’ve wasted your time.