I remember testing marmoset toolbag 4 beta, when baking curvature the bake would come out with pretty much no seam, much like painter in this screenshot. But I can't get the curvature bakes to look like that anymore. Wonder if something changed or I am missing something?
I am experiencing this same issue and what I notice is that if your low poly mesh has hard edges without bevel this will happen in toolbag only but not in painter. Areas that have bevel and have straight UV as much as possible bake just fine with very minor seam issue.
@Udjani ok so I did a test of marmoset curvature in Painter, I can see seam in curvature view, however so far I didnt notice seams when using mask generators and materials. My guess is its just how marmoset shows curvature